1Preheat oven to 350 °F. Line an 8*8 inch pan with parchment paper.
2Mix flour, baking soda, and salt.
3Set aside. Combine melted butter, brown and granulated sugar, egg, and vanilla.
4Whisk until smooth and fluffy for about 2-3 min.
5Add dry ingredients and chocolate chips. Mix until just combined.
6The browned butter mixture: Melt butter in a saucepan over medium-low heat.
7Stir every 10 seconds until foamy (6-8 minutes).
8Continue until milk solids turn golden brown and smell nutty. Transfer to a heatproof bowl.
9Add cocoa powder, oil, vanilla, and chopped chocolate; mix until smooth.
10In a separate bowl Whisk 3 eggs and light brown sugar for 5-6 minutes until dissolved.
11Add powdered sugar; mix 1-2 minutes until combined.
12Add cooled browned butter mixture; mix until smooth.
13Add flour and chocolate chips; mix until well combined. Note: Dissolving sugar in eggs ensures a crackly top.
14Layer the cookie and brownie batters in the prepared pan.
15Bake for 50-55 minutes or until the edges are golden and center is a little jiggly. They will set once they are completely cooled.
16Let cool completely before cutting into brookies.
Ingredients
0.5 cups unsalted butter, melted and cooled
0.5 cup light brown sugar
0.33 cup 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
1.5 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, 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
pinch salt
3 tbsp olive oil
Equipment
8*8 inch panparchment paper
Tips
You can adjust the layering to your preference, either by layering the cookie dough on top of the brownie batter or vice versa, or by creating a marbled effect by swirling the two batters together.