1Preheat oven to 350°F (175°C). Line an 8x8 inch baking 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 for about 2-3 minutes. Add dry ingredients and chocolate chips. Mix until just combined.
3Prepare brownie layer: Make browned butter by melting butter in a saucepan over medium-low heat, stirring constantly until golden brown and nutty. Transfer to a heatproof bowl.
4Add cocoa powder, oil, vanilla, and chopped chocolate to the browned butter; mix until smooth.
5Whisk 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.
6Layer the cookie and brownie batters in the prepared pan.
7Bake for 50-55 minutes or until the edges are golden and center is a little fudgy.
8Let 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 panwhiskspatulasaucepanmixing bowls