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This Big Batch Baked Oatmeal is great for a crowd but it’s even better as a make ahead breakfast! Oatmeal has healthy fiber, Greek yogurt and eggs give it a protein boost, and olive oil adds some healthy fat. The recipe mixes up in a flash and is one bowl easy. Plus, it’s infinitely adaptable. Bake it plain and let each person top their serving as they wish. Or, add your favorite toppings to the batter and let them bake right along with the oatmeal. 

Three squares of baked oatmeal on plates with different toppings

In my Cherry Crumb Bars post, I mentioned that everyone seems to be baking up a storm these days, evidenced by the fact that flour and yeast seem so hard to come by.

But is anyone else tired of cooking? I mean meal cooking…not baking up fun cookies and treats cooking…

Don’t get me wrong, I love to cook and bake…thus this blog. But, even when we’re not stuck at home, I like to take advantage of making big batches and having leftovers. It’s my whole cook once, eat 2 or 3 times philosophy.

In other words, I plan my breaks from cooking.

For instance…let’s talk about flipping some Fluffy Buttermilk Pancakes. I’d rather stand at the griddle and flip a few more pancakes today, than drag everything out and do it again tomorrow. (Plus, pancakes freeze beautifully, if you don’t want to eat them a couple of days in a row.)

Overhead view of Big Batch Baked Oatmeal in baking pan with rows of blueberries, chocolate chips and pecans and coconut baked on top.

Breakfast Strategies During Stay at Home

Do you want to know how I’m managing breakfast these days? We’re basically in a 3 day rotation of protein pancakes, this Big Batch Baked Oatmeal and something egg/egg white based. 

When there was no flour, I couldn’t make my own pancake recipes, so I bought big boxes of Kodiak Cakes Power Cakes. We buy them at BJ’s in boxes that contain 3 (20 ounce) bags. I doctor them up a bit, but one bag easily makes enough for 3 days of pancakes. 

Then, I created this Big Batch Oatmeal Recipe to make enough for 3 days of baked oatmeal. Do you see a pattern here?

Spatula lifting a square of Big Batch Baked Oatmeal out of baking pan

My husband often takes over on egg days, so do the math…I only have to make breakfast 2 times in over a week!

That doesn’t mean we’re not eating anything else for breakfast. I have whipped up things like my Brown Sugar Butter Pecan Scones or Fluffy Buttermilk Biscuits to add to an egg day. You know I LOVE making breakfast and brunch food…

And sometimes it’s just a fend for yourself day. Then some make eggs, some have cold cereal, some might go for whole wheat peanut butter toast or an individual bowl of traditional oatmeal.

But, right now, with limited supplies of certain ingredients and shopping less frequently, the rotation makes mornings so much easier. It’s my fall back if I don’t feel like getting crazy with making breakfast.

With this plan, breakfast is ready and everyone can easily move on to the day’s challenges, be they work or school.

And, if we happen to have a ripe avocado ready for toast, we might skip an oatmeal day for eggs and finish up the baked oatmeal the following day. Total flexibility.

Square of baked oatmeal resting on a spatula propped on the baking pan

What is Baked Oatmeal?

For all of you who already love baked oatmeal, you can skip this section and move on to the next.

I’ve said it before, but it bears saying again…Even though my baked oatmeal recipes might look like cake or muffins as in my original Baked Banana Oatmeal Cups, baked oatmeal is NOT cake. 

Some are disappointed when they take a bite and find that it’s quite moist, you know, like oatmeal! ;) It’s drier than traditionally prepared oatmeal. It’s like oatmeal that wanted to be a cake but never quite got there. :)

Traditional oatmeal is made with water and oats. This baked oatmeal adds eggs and yogurt and milk and olive oil as the wet ingredients. It also has baking powder. 

In the right proportion, the eggs add structure, the liquids and fats add moisture and the baking powder adds some lift. So, it’s sort of like cake, but much denser and much more moist. 

Even though you can cut it and pick it up…you can still eat it like oatmeal, in a bowl with milk and sugar. Think of it as a more versatile and more protein rich form of oatmeal.

Overhead view of three baked oatmeal squares topped with pecans and coconut, chocolate chips and blueberries

What kind of oats can I use for baked oatmeal?

You can make baked oatmeal with any kind of oats, but different oats react differently to moisture.

I generally use old fashioned rolled oats in my baked oatmeal recipes. I think it lends a great texture and heartiness to the recipe. So, I formulated this recipe using old fashioned rolled oats.

You could use quick oats in this same recipe, but the texture may turn out differently. My guess is that they may soak up more of the liquid. To combat that, you might need less oats than if you used old fashioned. Or, you might just like the new texture.

I would probably first try the exact amount of quick oats as rolled oats and see if I liked that. It’s going to be edible in any case, so there’s no risk in wasting ingredients. If I didn’t love that texture, I’d try backing the oats down to 5 1/4 cups instead of 6 and see how that turned out. 

I’ve been meaning to play around with grinding quick oats to oat flour in my food processor and see how we like the finer texture. On the other hand…

I’m also dying to develop a baked steel cut oat recipe; I’d love that extra bit of hearty texture. But for that, the ratio of liquid to oats would likely have to change again. You would likely need a lot less oats for steel cut. They’re going to need more moisture. 

Bottom line? Yes, you can make baked oatmeal with any sort of oat. But each type of oat will change the outcome. Experimenting is necessary to get the consistency you like best.

I would skip steel cut for this particular recipe. But, I think you can easily play around with subbing quick oats.

Two bowls, one showing eggs, yogurt, vanilla and olive oil in a mixing bowl and the other with the mixture combined

How to make baked oatmeal in one bowl

I’ve developed this recipe as a one bowl deal. The easier the better, right?

There is a little trick I use to insure we get a well mixed batter. Here’s how it goes…

First, you’ll mix up the eggs, yogurt, olive oil and vanilla. You want to get them nicely combined before you add the real liquid, the milk. Trust me. It will be much harder to break up and incorporate the eggs, if you add the milk with everything else.

When that first group of ingredients is whisked up, you’ll have a nice creamy mixture (right hand photo above).

Now, whisk in the milk. The mixture will now be much thinner, but it will be well combined.

Two mixing bowls, one showing the milk and yogurt mixture, the other with oats floating on top of the mixture

Time for the oats. Measure out your oats right on top of the milk mixture, but DO NOT STIR yet! We need them to sit quietly on top of the milk mixture while we add the rest of our dry ingredients.

Sprinkle the salt, cinnamon and baking powder evenly over the oats. Do this instead of just dropping them in piles on top. This will help distribute it more evenly when you start to stir. 

Then, all you’ve got to do is mix it up! I like to start by lifting the bottom mixture and pulling it over the top. Then turn the bowl and repeat and repeat until I’ve submerged all of the oats. Then, I just stir.

Do you have to follow this exact stirring process? No, but I do find it gives the dry ingredients a better chance of even distribution. (Or, at least I’d like to think so :)

I usually use the cinnamon as my clue. Once I see those flecks of cinnamon mixed throughout the batter and the oats are completely saturated with the wet ingredients, I’m done. Just pour it in the pan and bake.

Three mixing bowls showing the addition of dry ingredients and then the final mixed batter

Can I make baked oatmeal ahead of time?

Yes. Absolutely. We’re planning for leftovers anyway, right?  In fact, I almost always make it the night before so that I’m already starting day one without having to cook breakfast. #sleepingoals

Overhead view of Big Batch Oatmeal batter in baking pan before baking

How much sweetener should I add to the recipe?

You’ll see that I’ve added zero, zilch, nada. Why? Because this has become a base recipe for infinite combinations. I started by making it with some sugar, but my family started to vote no on sugar in the recipe. (Wait, what?!? lol!)

They preferred to customize their individual bowls to their own taste depending upon how they felt that day. This works swimmingly for me because I like to control how much sugar is in my bowl.

In my other baked oatmeal recipes, there is usually some sweetness included in the recipe. 

My Blueberry Pie Baked Oatmeal had no sugar in the oat part because it’s topped with a sweet crumb topping.

But in my Baked Apple Oatmeal, there’s 1/4 cup of brown sugar in the oatmeal mixture as well as a sweet crisp/crumb topping. Of course, there’s sweetness in both of those recipes from the fruit.

Fruit also adds sweetness in this Ultimate Carrot Cake Baked Oatmeal, but yes, there’s some brown sugar in the oat mixture as well.

So, I repeat, there’s NO added sugar in THIS Big Batch Baked Oatmeal base recipe. 

However, if you want that sweetness right off the start? Use this chart to figure out how much sweetness to add:

If you normally add this
amount of sugar/sweetener
to ONE bowl of oatmeal
Add this amount
of sugar/sweetener to
the whole recipe
1 teaspoon 1/4 cup
2 teaspoons 1/2 cup
3 teaspoons 3/4 cup

If you normally add this
amount of sugar/sweetener
to ONE bowl of oatmeal
Add this amount
of sugar/sweetener to
the whole recipe
1 teaspoon 1/4 cup
2 teaspoons 1/2 cup
3 teaspoons 3/4 cup

What kind of sweeteners can I use?

Feel free to use your favorite sweetener like white granulated sugar, brown sugar, honey, maple syrup or agave syrup. Of course, alternative sweeteners can be used as well. Just be sure if you’re adding it before baking, that it’s a sweetener that can be used in baked recipes.

If you use a dry sweetener like sugar, add it along with the cinnamon etc, on top of the dry oats. Or, feel free to sprinkle it over the top of the oats once you pour them in the pan if you want a sugary topping.

If you use a liquid sweetener like maple syrup, add it when you’re mixing the yogurt and eggs. 

If you use a liquid sweetener, we need to balance the liquid in the recipe. I would reduce the milk by about 1 Tablespoon for every 1/4 cup of liquid sweetener. So, if you use 3/4 cup of maple syrup, I would take out 3-4 Tablespoons of milk. 

Also, if you end up using a milk that has sweetener added, you might want to reduce the amount of sugar you add.

Overhead view of unbaked oatmeal with blueberries, chocolate chips and pecans and coconut sprinkled in sections on top

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Can I use any kind of milk in this recipe?

Yes. Feel free to substitute any kind of milk you like….coconut milk {aff. link}, almond milk, rice milk, oat milk {aff. link} You can even substitute water, if you don’t want to use milk.

I like to use unsweetened vanilla almond milk {aff. link} in this recipe. Those 4 cup cartons hold the perfect amount and the vanilla flavor is an added flavor boost to the vanilla extract. 

Of course, this also goes back to the whole stay at home shopping issue. We still buy fresh milk when we shop, but we’ve stocked up on almond milk and it’s turned out to be a great pantry item for this recipe.

And, because I can use the whole carton, left overs are not forgotten in the refrigerator.

Overhead view of a square of baked oatmeal with blueberries on top next to a pitcher of milk

Is there a substitute for the Greek yogurt?

The reason I add the Greek yogurt is primarily for the extra protein and calcium boost, but I really love how it works with the recipe as well.

That being said, if you want to skip it, just increase the milk from 4 cups to 5 1/2 cups.

Or, keep the milk the same and sub in mashed banana for the yogurt. You could use applesauce, but I’d probably only use 1 1/2 cups, since it has so much water.

Square of baked oatmeal with chocolate chips being placed on a plate.

Can I substitute the olive oil?

Yes. You can use coconut oil, canola, vegetable, sunflower, etc. Use your favorite oil.

The bonus with using olive oil is that you don’t have to worry about bringing anything to room temperature or having an added step of melting something. And, it’s a healthier oil, so it’s my personal pick for this.

Melted butter would also be delish. The only issue with melted butter is that it will resolidify when it hits the cold ingredients. So you might see bits of butter floating around your mixture. I don’t think that will make a huge difference as it would with a cake. 

Overhead view of 4 squares of baked oatmeal with different toppings

This recipe is infinitely adaptable

Well, I’ve already told you about the numerous substitutions you can make for this recipe. It’s already infinitely adaptable and we haven’t even gotten to toppings!

In some of my fancier flavored baked oatmeal, just mentioned above, you can see some really fun variations. I adore each and every one of those recipes. If I do say so myself, in the realm of baked oatmeal, some of them are really quite special. 

This recipe, however, was meant to be a blank slate.

But… blank slates are kind of boring to photograph, so I added some toppings before I baked the oatmeal.

In these photos, you’ll see blueberries, chocolate chips and a pecan/coconut mixture sprinkled in different sections on top of the oatmeal. These were very simple additions that I had either in my pantry or freezer.

And, even though my family likes to handle their toppings on their own, it’s fun to bake some toppings right into the oatmeal. 

Overhead view of chocolate chip baked oatmeal with a bowl of raw sugar

Topping ideas to add before baking:

  • Any kind of chip… chocolate, white chocolate, caramel, cinnamon, peanut butter
  • Heath toffee chips
  • Nuts
  • Granola
  • Dried fruit like raisins or dates or cherries
  • Fresh fruits like blueberries, chopped or sliced strawberries, apples, bananas 
  • Go savory and add shredded cheese, scallions, bacon or chives

You can also use frozen fruits, but they will give off more moisture, so they may make the top of your oatmeal a little wetter. If that bothers you, stick with dry and fresh fruit. Again, if you’re an oatmeal lover, it’s all going to be deliciously edible in the end, but you may find you have a preference for less moisture.

My blueberries were frozen. I just rinsed them. Because of how long it takes to photograph, they were probably mostly thawed by the time I baked the oatmeal.

By the way…feel free to take any of those toppings and mix them right into the oatmeal. They don’t have to be baked on top!

Square of baked oatmeal with blueberries baked on top

Topping/serving ideas to add after baking:

So…let’s say you roll like we do and you’ve baked up a big batch of plain baked oatmeal. Well, my friend, the world is your oyster.

You can obviously use any toppings above, but here are some other ideas:

  • Spread peanut butter on top and sprinkle with chocolate chips
  • Spread Nutella on top and add some sliced bananas
  • Add fresh berries and cream
  • Add a pat of salted butter and drizzle with maple syrup
  • Drizzle with honey
  • Go classic and add walnuts, brown sugar and cinnamon
  • Add yogurt or cottage cheese along with some fresh fruit
  • Top with granola or other cereal for extra texture

Really, the options are endless! These are just a few ideas to get you thinking. And, because there are so many ideas, each bowl of oatmeal can be different, so you don’t have to eat exactly the same version everyday, if you don’t want to.

Now, depending upon how you made your individual creation, you can either pick that oatmeal up with your hand, scoop it up with a spoon or spear it with a fork.

What’s really important is this…assuming you’ve got a house full of four oatmeal lovers (or in my case, 1 oatmeal lover, 1 oatmeal eater and 2 oatmeal accepters :) …

Breakfast is now done for today, tomorrow and the next day! 

 

Overhead view of three baked oatmeal squares topped with pecans and coconut, chocolate chips and blueberries

Big Batch Baked Oatmeal

Yield: 12 servings
Prep Time: 10 minutes
Cook Time: 45 minutes
Total Time: 55 minutes

This Big Batch Baked Oatmeal is great for a crowd but it’s even better as a make ahead breakfast! Oatmeal has healthy fiber, Greek yogurt and eggs give it a protein boost, and olive oil adds some healthy fat. The recipe mixes up in a flash and is one bowl easy. Plus, it’s infinitely adaptable. Bake it plain and let each person top their serving as they wish. Or, add your favorite toppings to the batter and let them bake right along with the oatmeal. 

Ingredients

Wet Ingredients

  • 2 cups plain Greek Yogurt (I use Fage 2%)
  • 1/4 cup olive oil
  • 4 large eggs
  • 2 teaspoons vanilla
  • 4 cups milk (I use unsweetened vanilla almond milk)

Dry Ingredients

  • 6 cups old fashioned rolled oats
  • 1 teaspoon salt
  • 4 teaspoons baking powder
  • 2 teaspoons cinnamon

Optional toppings:

  • chocolate chips
  • pecans
  • shredded coconut
  • blueberries

Instructions

  1. Preheat oven to 350 degrees F. Spray a 9 x 13 baking pan with olive oil or cooking spray.
  2. In a large mixing bowl, whisk together the yogurt, olive oil, eggs and vanilla until well combined. Whisk in the milk.
  3. Pour oats evenly over the milk mixture but do not stir. This will create a "bed" for the rest of your dry ingredients.
  4. Sprinkle salt, baking powder and cinnamon evenly over the top of the oats. Stir until well combined. I like to check to see the cinnamon mixed evenly throughout the batter as a clue to how well it's combined.
  5. Pour mixture into prepared pan, spreading oats evenly. At this point, you can bake it plain and add your favorite toppings later or sprinkle fruit, nuts, chocolate or other toppings right on top before baking.
  6. Bake for 40-45 minutes until firm to the touch, lightly golden on top and a little golden brown around the edges. (I always bake mine for 45 min) Allow to cool for 5 or 10 minutes before cutting.
  7. Cut into 12 squares and serve. Store leftovers in refrigerator and reheat in microwave.

Notes

*This is baked oatmeal, so even though it might look like a muffiny cake, the texture is much more moist. It's not wet like a bowl of oatmeal, but you wouldn't mistake it for cake.

*There is NO added sugar in this recipe. We like to add toppings and sweeteners to our own individual bowls. If you'd like to add sugar or other sweetener, use the chart in the blog post as a guide for how much to add to the recipe. Just add it along with the salt, baking powder and cinnamon.

*Old fashioned oats are best for this recipe. I've never made it with quick oats, but you can experiment. I think they might absorb more liquid, so you might have to reduce the quantity of oats.

*I love adding the vanilla almond milk. It's great because I don't have to measure. I just use the whole 4 cup carton. Between that and the vanilla extract and cinnamon, it just smells amazing while it's baking. However, you can use any kind of milk you like. You can even substitute water.

*Sprinkling the salt, baking powder and spices evenly over the dry oats helps with getting them evenly incorporated in this one bowl recipe. If you add the cinnamon directly into the liquid, for instance, it's more likely to clump.

*This recipe is infinitely adaptable. Add all kinds of toppings before baking or after baking. Eat the oatmeal with a fork or break it up and pour milk over it in a bowl and eat with a spoon.

*I give lots of ideas for substitutions for the milk, oil and yogurt in the post. Check out the post for lots of adapatable ideas!