1Preheat oven to 350°F (175°C). Line an 8x8 inch pan with parchment paper.
2Prepare the cookie layer: Mix flour, baking soda, and salt. Set aside. Combine melted butter, brown and granulated sugar, egg, and vanilla. Whisk until smooth and fluffy for about 2-3 minutes. Add dry ingredients and chocolate chips. Mix until just combined.
3Prepare the brownie layer: Make browned butter: Melt butter in a saucepan over medium-low heat. Stir every 10 seconds until foamy (6-8 minutes). Continue until milk solids turn golden brown and smell nutty. Transfer to a heatproof bowl. Add cocoa powder, oil, vanilla, and chopped chocolate; mix until smooth. In a separate bowl whisk 3 eggs and light brown sugar for 5-6 minutes until dissolved. Add powdered sugar; mix 1-2 minutes until combined. Add cooled browned butter mixture; mix until smooth. Add flour and chocolate chips; mix until well combined.
4Layer the cookie and brownie batters in the prepared pan.
5Bake for 50-55 minutes or until the edges are golden and the center is a little fudgy.
6Let cool completely before cutting into brookies.
Ingredients
0.5 cup unsalted butter
0.5 cup light brown sugar
0.33 cup granulated sugar
1 large egg
1 tbsp vanilla extract
1.25 cups all-purpose flour
0.5 tsp baking soda
1 pinch salt
1.5 cups semi-sweet chocolate chips
1 cup unsalted butter
0.5 cup cocoa powder
1 teaspoon vanilla extract
0.5 cup light brown sugar
1.75 cups powdered sugar
0.75 cup semi-sweet chocolate chips
0.33 cup semi-sweet chocolate
3 large eggs
0.5 cup all-purpose flour
1 pinch salt
3 tablespoons olive oil
Equipment
8*8 inch baking panparchment papermixing bowlswhiskspatulasaucepan