Chocolate Fudge Brownies with Chocolate Buttercream Frosting Ingredients For the brownies: 3/4 cup AP flour 1 tsp baking powder 1/2 tsp salt 1/2 cup butter 3 oz unsweetened chocolate 1/2 cup packed brown sugar 1/2 cup granulated sugar 2 large eggs 1 large egg yolk 1 tsp vanilla extract 1/2 cup semisweet chocolate chips