This Brookie recipe is quick to make with a base batter that's easy to assemble in one-bowl and then transformed into a layer of brownies topped with dollops of chocolate chip cookie dough for decadent, amazing, from-scratch cookie bars!
Preheat oven to 350°F. Grease a 9- by 13-inch baking pan and set aside.
Add the melted butter to a large bowl. Use a wooden spoon to stir in the brown sugar until well-combined. Beat in the eggs and vanilla until completely incorporated. Blend in the flour and salt until smooth and fully blended. Divide the dough in half, transferring one portion to a separate bowl.
Stir the chocolate chips into one bowl. Stir the cocoa powder and additional egg into the other bowl until completely incorporated.
Spread about ¾ of the brownie batter into the bottom of the prepared pan. Spoon the chocolate chip cookie dough in dollops over the brownie batter. Distribute small spoonfuls of the remaining brownie batter between the cookie dough dollops (to give the Brookies a marbled look once they finish baking).
Bake for 20 to 25 minutes or until the center is set. Set pan on wire rack to cool completely before slicing.
Notes
I like to use a baking pan with square edges, like this one.
I prefer greasing my pan with softened butter and then lining it with parchment paper (the butter holds it in place).
Some people prefer gooey Brookies and some people prefer them firmer. Either way, keep in mind that these are very dense, moist cookie bars that may seem a tad underdone when you first pull them out of the oven. They will continue to set and firm up as they cool. The first time you make this recipe, take note of the specific baking time for your oven that achieves your optimal Brookie texture (the perfect time in my particular oven is 21-22 minutes, but yours may vary).
The center pieces will be softer/gooier than the edge pieces. If you prefer firmer edge pieces over gooey center pieces, simply divide your Brookie recipe between two 8- by 8-inch pans instead of using a 9- by 13-inch pan.