Melt the butter in a microwave-safe bowl for 30 seconds to one minute. In a mixing bowl, combine the melted butter, sugar, flour, cocoa powder, and eggs. Stir until smooth. Fold in the chocolate chips.

Line a 9-inch square baking dish with parchment paper. Pour the batter into the dish and spread evenly. Bake in a preheated oven at 350°F for 25 minutes or until a toothpick inserted in the center comes out with moist crumbs.

Allow the brownies to cool completely. Optionally, dust the top with powdered sugar before serving.