Instructions

• Preheat the oven to 350°F (175°C). Line a 13 x 9 x 2-inch baking dish with parchment paper (leave a slight overhang for easy removal) and set aside.
• In a medium mixing bowl combine 1 cup melted butter, 1 cup granulated sugar, and 1 cup brown sugar. Stir or beat until combined.
• Add the 4 large eggs, one at a time, mixing after each addition. Add 1 teaspoon vanilla extract and mix until smooth.
• In a separate bowl whisk together 2 cups all-purpose flour, 1/3 cup unsweetened cocoa powder, 1 teaspoon baking powder, and 1/2 teaspoon salt.
• Gradually add the dry ingredients to the wet ingredients, mixing until just combined and no large streaks of flour remain. Scrape the sides and bottom of the bowl as needed.
• Spread the brownie batter evenly into the prepared baking dish and smooth the top with a spatula.
• Bake for 30–35 minutes, or until a toothpick inserted into the center comes out clean. Remove from the oven and place the pan on a wire rack to cool completely in the pan.
• While the brownies cool, make the cookie-dough frosting: in a medium bowl combine 1/2 cup softened butter and 3/4 cup brown sugar. Beat with a hand mixer until smooth and lighter in color.
• Add 1 teaspoon vanilla extract and mix to combine.
• Add 1 1/4 cups all-purpose flour and 1/2 teaspoon salt. Mix on low speed until the flour is incorporated and the mixture is crumbly.
• Pour in 5 tablespoons milk and beat until the mixture becomes thick and fluffy and reaches a spreadable consistency.
• Stir in 1 cup mini chocolate chips until evenly distributed.
• Once the brownies are completely cool, spread the cookie-dough frosting evenly over the top. Use the parchment overhang to lift the brownies from the pan before cutting, if desired.