In a medium saucepan, melt 1 cup of unsalted butter over medium heat, stirring frequently until it turns golden brown and releases a nutty aroma, about 5-7 minutes. Chill in the refrigerator for about 1 hour.

In a mixing bowl, combine the cooled brown butter with ½ cup granulated sugar and ½ cup light brown sugar, whisking until smooth. Add 1 large egg and mix thoroughly.

Gradually add 1½ cups all-purpose flour, ½ teaspoon baking soda, and a pinch of salt. Fold in 1 cup of chocolate chips.

Melt 4 ounces of bittersweet chocolate with ½ cup unsalted butter in a heatproof bowl over simmering water. Stir until smooth. Remove from heat and mix in ¾ cup granulated sugar, 1 large egg, and 1 teaspoon vanilla extract.

Stir in ½ cup all-purpose flour until just combined. Preheat your oven to 350°F (175°C).

In an 8x8 inch baking pan, spoon half of the brownie batter into the bottom. Layer all of the cookie dough over the brownie base, then drop remaining brownie batter on top, swirling slightly with a spatula.

Bake for 25-30 minutes. They are done when the edges are set, but the center remains slightly gooey.

Let your brookies cool in the pan for at least 20 minutes. Slice into squares and enjoy.