Preheat oven to 350 degrees F. Line a 13 x 9" pan with foil. Spray foil lined pan with cooking spray.
In a medium bowl, whisk together, flour, baking powder, baking soda, cornstarch and salt. Set aside.
In a large mixing bowl, beat butter and sugars until fluffy, about 3 minutes.
Add vanilla and eggs, adding eggs one at a time, mixing until thoroughly combined.
Gradually add flour mixture beating until mostly combined. It's okay to leave some flour streaks.
Add chips and mix until evenly distributed in batter and dry ingredients are no longer visible.
Take about 2/3 of the cookie dough and pat it evenly in prepared pan. (I used a layer of plastic wrap to press the dough into the pan and keep it from sticking to my hands.)
Empty the dulce de leche into a microwave save bowl and heat briefly, maybe 30 seconds, or until easy to spread. Check and stir at 15 second intervals. Don't overheat or you'll have to wait for it to cool down before spreading on dough. You just want to soften it a little.
Spread dulce de leche evenly over cookie dough, leaving about a 1/2" border along the edges.
Drop the remaining cookie dough by spoonfuls evenly over the dulce de leche layer.
Sprinkle chopped pecans over the top of the cookie dough, if using. They will likely nestle in between the mounds of cookie dough. That's fine.
Finally, sprinkle fleur de sel evenly over all.
Bake for 20-25 minutes or until golden brown.
Allow to fully cool before cutting into bars. Store leftovers in an airtight container in the refrigerator.
*For those with convection ovens, bake at 325 for about 25 minutes.
*If you don't have flaky sea salt, don't just sprinkle table salt on top. It will likely be too salty. A flaky or coarse salt is best for both flavor and texture. I tried 1/4 teaspoon and wish I would have used a 1/2 teaspoon, which is what I put in the recipe. It's better to be conservative so that you don't over salt. Remember that 1/2 teaspoon of coarse salt is not the same as measuring the same amount of fine grain salt. Less fits into the spoon. In this case, err on the lighter side.
*You don't have to use the exact amount of of dulce de leche that I did. Different brands come in different sizes. Just use close to the amount so you can get a nice layer of caramel in your bar.
*You can use one kind of chocolate chips or mix different kinds. If you like a sweeter bar, use milk chocolate, or a combo of milk and semisweet.
*I used 3 cups of chocolate chips, 1 cup was bittersweet, the other 2 cups were semisweet. 3 cups is about 18 ounces of chips. The bars were chock full of chips which many loved. I might reduce the chips to 2 or 2 1/2 cups next time.
*The bars are delicious and chewy when cold or room temperature. When warmed for a few seconds in the microwave, the chocolate melts, and the cookie and dulce de leche soften. When warm, they are the perfect base for a scoop of ice cream.
*The bars are hearty. I cut mine into 24 bars for the post, but you could definitely cut into smaller bars and easily get 36-48 smaller servings.
_The Merchant Baker Copyright © 2017