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Lemon Blueberry Shortbread Bars

If you’ve been following along, you probably would have noticed the trail of crumbs that led to these Lemon Blueberry Shortbread Bars. (If you haven’t been following along…now is as good a time as any to start ;)

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

I’ve had some lemon features on my home page and posted a new Lemon Blueberry Cheesecake Dip. It’s clear I have a love for lemon and I’ve continued to think about lemons…

Then there’s the crumb situation…After the last piece of Chocolate Chip Crumb Cake was consumed, I was still craving crumbs, or more specifically, crumb topping.

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

The last piece of this puzzle came when a good friend was recently recuperating at home. I knew she had a fondness for some lemon cream crumb bars from a recipe I had made for her a few years ago.

They were the kind of crumb bar where the mixture you use for the crust is the same mixture you use for the crumb topping. So I baked her a pan of them and delivered them to her house.

I thought that would relieve the need to make something crumb topped, even though that crumb topped treat was not one that was going to stay in our house. So, I decided to create a new crumb topped bar. I was going to develop something on my own. Perhaps it would become a new favorite.

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

I started with the shortbread base that I created for Millionaire Magic Bars. It’s a delicious base for a bar. It’s softer than traditional shortbread and perfect if you want more moisture in your base.

I was wrestling with whether or not I should cut the shortbread recipe in half and make a thinner crust. If I cut the recipe in half, I was going to have to divide an egg and use half of it. That’s not hard, but I wasn’t in the mood to post a recipe with half an egg in it, so I decided to go big and see where it led me. I parbaked the crust and moved on.

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

Next up, the filling. I wanted a pie-like filling, something creamy, like you might find in a lemon tart. Sweetened condensed milk is the magic behind such a filling.

And, with just a few extra ingredients stirred into it, you quickly and easily get a lovely lemon custard. I went with a full 2 Tablespoons of lemon zest in the filling. I wanted to insure the lemon flavor was front and center.

That was supposed to be it for the filling. Just the lemon custard. Until I happened upon some nice, plump, fresh organic blueberries. They’ve been a bit difficult to find this year, what with all the crazy weather conditions affecting the harvest.

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

What to do? What to do? I had really planned on simple lemon cream crumb bars, but those blueberries won me over. Fine. I decided to add blueberries. I scattered them on top of the par baked crust and then poured the lemon custard over all.

Now for the crumb topping…I went with the crumb topping I made for the Chocolate Chip Crumb Cake with three changes…First, I used white sugar instead of brown sugar. I didn’t want that extra note of molasses in these bars. I wanted a cleaner crumb flavor. And, I wanted a nice light colored crumb.

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

Second, I didn’t use melted butter. That’s right. I gave you the easy way out with that last recipe. It had a moist New York kind of crumb. I didn’t want a moist crumb for this bar. I already had a soft base with the shortbread. I needed some textural difference for the topping.

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

So guess what? We’re back to embracing working cold butter into the flour mixture. Think of it as meditative. You can’t screw this up. Just squeeze the butter into the flour mixture working it in and working it in until the whole mixture gets sandy and can hold together if you squeeze any part of it.

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

Third, and this part is optional, I added lemon juice powder. I talk all about this ingredient in one of my favorites posts. I’m loving real fruit powders. It’s a wonderful way to punch up fruity flavors in recipes where a juicy fruit won’t work quite so well. I used raspberry powder in these sugar cookies and the flavor was fantastic. They taste like real fruit because, well, they are real fruit.

I’ve mentioned before that I would add lemon juice powder to many of my posted lemon recipes save for the fact that it’s not a standard pantry item for most of you.

So, my crumb topping wasn’t just any crumb topping, it was lemon crumb topping. No lemon powder in your pantry? Add lemon zest instead. It’s all good.

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

After these bars come out of the oven, you’re going to have to exercise some patience. They need to completely cool and then refrigerate to set up further, similar to how cheesecake needs to have its time to set up.

Once cool, the bars are easily lifted up and out of the pan by the foil lining that I advise you to use in the recipe. Then, I used a serrated edged knife to cut them. This keeps the crumbs on the top of the bar instead of getting pushed into the bar as can happen with a non-serrated edge.

It also prevents your berries from getting crushed. Use the sawing motion just to get through the crust and the filling. Once you hit the bottom crust, you can add pressure and cut right through.

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

The bar was a hit for everyone, except for me, the one who was still questioning whether or not I should have made a thinner crust. Or, if I was happy with what all my various components ended up as once they became a whole.

Because, what I made, wasn’t anything like the lemon cream crumb bar that I had made for my friend. It was a Whole. Different. Thing. Not really a crumb bar, kinda like a pie…except, kinda not.

As far as the shortbread, hands down everyone liked it thick. Amount of lemon flavor? Not too tart and not too sweet, and plenty of lemon flavor without being overpowering. Juicy blueberries? Check. No one would change a thing. Crumb topping? Forget it. Crumb topped anything in any form is a go with this crew.

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

So what was my problem? I guess I didn’t end up with what I had started out to create. These weren’t lemon cream crumb bars. They were Lemon Blueberry Shortbread Bars. Because of the thick, soft, buttery crust, the shortbread is the most prominent thing about these bars. Everything else is like a bunch of wonderfully delicious accessories to the shortbread, crumbs included.

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

Okay, then. I made Lemon Blueberry Shortbread Bars. I’ve come through the acceptance curve. And while I probably won’t be able to hold back from trying different versions of the crust and filling when I make them in the future, (which is an ongoing issue with any recipe I develop) I embrace this version whole heartedly.

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

I’m flexible like that :)

Lemon Blueberry Shortbread Bars. A thick, soft shortbread crust is topped with a lemony custard, fresh blueberries and a lemon crumb topping!

Lemon Blueberry Shortbread Bars

Yield: 16 bars

Ingredients

For the shortbread crust:

  • 2 cups all purpose flour
  • 1 Tablespoon cornstarch
  • 1 cup salted butter room temperature
  • 1 cup granulated sugar
  • 1 large egg room temperature
  • 1 teaspoon vanilla extract

For the lemon crumb topping:

  • 3/4 cup all purpose flour
  • 1/2 cup granulated sugar
  • 1 Tablespoon lemon juice powder optional or see notes for substitution
  • 4 Tablespoons unsalted butter cold and cut into small pieces

For the filling:

  • 1 14 ounce can sweetened condensed milk
  • 2 large eggs
  • 2 Tablespoons lemon zest I used about 3 lemons for this
  • 1/2 cup fresh squeezed lemon juice
  • 2 cups fresh blueberries

To garnish before serving:

  • Confectioner's sugar

Instructions

  1. Preheat oven to 350 degrees F. Line a 9" square pan with foil, then grease or spray bottom and sides with cooking spray.

  2. Make the shortbread crust. In a medium bowl, whisk together flour and cornstarch. Set aside.

  3. In a large bowl, beat softened butter and sugar together until light and fluffy, about 2-3 minutes.

  4. Add the egg and vanilla and beat until well combined.

  5. On low speed, gradually add the flour mixture and mix until combined.

  6. Scoop the dough into prepared pan, and using a layer of plastic wrap, press the dough evenly into the pan. (The plastic wrap will keep the dough from sticking to your hands. Lift and move the plastic wrap around as necessary to get the dough evenly pressed into the pan.)

  7. Bake for 15 minutes, then set aside to cool.

  8. While the crust is baking and cooling, make the crumb topping. In a medium bowl, whisk together the flour, sugar and lemon powder, if using.

  9. Add the cold butter pieces and, using your hands, work the butter into the flour mixture until the whole mixture becomes sandy. There should be no visible pieces of butter left. It should be completely worked into the flour. You should be able to squeeze any part of the mixture and have it hold together. This will take you 2-3 minutes. Set aside.

  10. Make the filling. In a large bowl, whisk together the sweetened condensed milk, eggs, lemon zest and lemon juice until fully combined.

  11. Spread blueberries in one layer over pre-baked shortbread crust. The crust doesn't have to be completely cool. It's fine if it's just been cooling for 10-15 minutes.

  12. Pour lemon filling over blueberries and spread evenly to make sure it fills in all the spaces between the berries and fills in to the edges of the pan. Tap the pan on your work surface to release any air bubbles and to help the filling to settle into the pan.

  13. Squeeze handfuls of the crumb topping together, then break apart various sized crumbs sprinkling evenly over the top. Gently press crumbs into lemon blueberry layer with flat hands.

  14. Bake for 30-35 minutes or until it starts to get just lightly golden around the edges.

  15. Allow to completely cool. Then, refrigerate for a couple of hours or overnight until chilled through and set.

  16. Use the foil to lift the bars out of the pan for cutting. I use a serrated knife to keep the crumb topping intact. Sprinkle bars with confectioner's sugar. Store bars in the refrigerator.

Notes

*Always remember to zest your lemons before juicing them.

*If you don't have lemon powder to add to your crumb topping but would still like that lemon flavor, just add the zest of one lemon to the topping mixture before you work in the butter.

*I baked mine about 30 minutes. I would probably push it another 5 minutes the next time.

*If you want to try a thinner crust, go ahead and cut that part of the recipe in half. To cut the egg in half, just lightly beat one egg and then take about 2 Tablespoons out for the recipe.

*I would not use an 8" square pan unless you cut the crust recipe in half.

The Merchant Baker Copyright © 2017

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Claudia

Sunday 3rd of September 2017

These were delicious - my family LOVED them. I accidentally used an 8 x 8" pan the first time and although it worked, they were very very thick and slightly undercooked. The second time I made them, I used a 7 x 11" pan (I don't have a 9 x 9" pan, so was trying to find something that would work in a pinch), that worked much better, BUT I needed to cook the shortbread in the beginning for just a little bit longer (about 5-7min). Really great! Thank you!

Ramona

Sunday 3rd of September 2017

Claudia, for so long, I didn't have a 7 x 11 pan and was always a bit frustrated when I came upon a recipe that called for one. I finally went out and bought one years ago so that I wouldn't be without that size. It's funny that that's the pan you have! In any case, 7 x 11 gives you 77 square inches vs. the 9 x 9 which gives you 81 inches. It's so close and a great sub for a 9 x 9. Thanks for sticking with the recipe and figuring out how to alter it for a different sized pan. I'm so glad it worked out for you!

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