For the Brownie Layer: – 1 cup (225 g) unsalted butter – 2 cups (400 g) granulated sugar – 4 large egg – 1 teaspoon vanilla extract – 1 cup (120 g) all-purpose flour – 3/4 cup (90 g) unsweetened cocoa powder – 1/2 teaspoon salt – 1/2 teaspoon baking powder For the Cookie Dough Layer: – 1/2 cup (115 g) unsalted butter, softened – 3/4 cup (150 g) light brown sugar, packed – 1/4 cup (50 g) granulated sugar – 2 tablespoons milk or cream – 1 teaspoon vanilla extract – 1 1/2 cups (180 g) all-purpose flour – 1/2 teaspoon salt – 1 cup (175 g) chocolate chip
Warm the oven up to 175°F (350°F). A 9x13-inch baking pan should be greased or lined with parchment paper. Melt the butter for the brownie layer in a bowl that can go in the microwave. Add the granulated sugar and mix it in well. Add the eggs one at a time and beat well. Then add the vanilla extract.
Mix the flour and salt into the wet ingredients slowly at first, until a smooth dough forms. The chocolate chips should be spread out evenly after being added. On top of the brownie batter, drop spoonfuls of the cookie dough and then gently spread it out to cover the whole top.
Before you put it in the oven, heat it up. Bake for 25 to 30 minutes, or until the edges are set and a toothpick pushed into the middle comes out with a few moist crumbs on it. Before cutting the brownies into pieces, let them cool all the way in the pan.