Brownie Sandwich Cookies with Chocolate Chip Cookie Dough Frosting Ingredients 1/2 cup unsalted butter 2 cups semi-sweet chocolate chips 1 1/2 cups all-purpose flour 1/4 cup dutch processed cocoa powder 1/2 tsp baking powder 1/4 tsp baking soda 1 tsp salt 1/2 cup packed light-brown sugar 1/2 cup granulated sugar 3 large eggs 1 tbsp