1Preheat oven to 350°F (175°C). Line an 8x8 inch pan with parchment paper.
2Prepare 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 (2-3 minutes). Add dry ingredients and chocolate chips. Mix until just combined.
3Prepare brownie layer: Make browned butter: Melt butter in a saucepan over medium-low heat, stirring 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.
4Whisk 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.
5Layer cookie and brownie batters in the prepared pan.
6Bake for 40-45 minutes, or until edges are golden and the center is only slightly jiggly (it will set completely once cooled).
7Let cool completely before cutting into brookies.
Ingredients
0.5 cups unsalted butter, melted and cooled
0.5 cups light brown sugar
0.33 cups granulated sugar
1 large egg, room temp
1 tbsp vanilla extract
1.25 cups all-purpose flour, spooned and leveled
0.5 tsp baking soda
0.5 tsp flaky sea salt
1 cup semi-sweet chocolate chips
1 cup unsalted butter
0.5 cup cocoa powder
1 tsp vanilla extract
0.5 cup light brown sugar, spooned and leveled
1.75 cup powdered sugar
0.75 cup semi-sweet chocolate chips
0.33 cup semi-sweet chocolate, chopped
3 eggs, room temp
0.5 cup all-purpose flour
1 pinch salt
3 tbsp olive oil
Equipment
8x8 inch baking panparchment paperwhisksaucepanspatulamixing bowls