1Prepare the cookie layer: In a bowl, mix flour, baking soda, and salt. In another bowl, combine melted butter, brown and granulated sugar, egg, and vanilla. Whisk until smooth and fluffy. Add dry ingredients and chocolate chips. Mix until just combined.
2Prepare the brownie layer: Make the browned butter mixture by melting butter in a saucepan over medium-low heat, stirring until foamy. Continue until milk solids turn golden brown. Transfer to a bowl. Add cocoa powder, oil, vanilla, and chopped chocolate; mix until smooth. In a separate bowl, whisk 3 eggs and light brown sugar until dissolved. Add powdered sugar; mix. Add cooled browned butter mixture; mix until smooth. Add flour and chocolate chips; mix well.
3Preheat oven to 350°F (175°C). Line an 8x8 inch pan with parchment paper.
4Layer the cookie and brownie batters in the prepared pan. Spread the brownie batter first, then drop spoonfuls of cookie dough over the brownies. Cover with remaining brownie batter and add chocolate chips on top.
5Bake for 50-55 minutes, or until edges are golden and the center is a little fudgy.
6Let cool completely before cutting into brookies.
Ingredients
0.5 cups unsalted butter
0.5 cups light brown sugar
0.33 cups granulated sugar
1 large egg
1 tbsp vanilla extract
1.25 cups all-purpose flour
0.5 tsp baking soda
0.5 tsp flaky sea salt
1.5 cups semi-sweet chocolate chips
1 cup unsalted butter
0.5 cup Dutch-processed cocoa powder
1 tsp vanilla
0.5 cup light brown sugar
1.75 cups powdered sugar
0.75 cups semi-sweet chocolate chips
0.33 cups semi-sweet chocolate
3 eggs
0.5 cup all-purpose flour
1 pinch salt
3 tbsp olive oil
Equipment
8x8 inch baking panparchment paperwhiskspatulasaucepanheatproof bowl