Cappuccino Frosting with flour

2 cups flour 4 teaspoons baking powder 2 teaspoons salt 1 1/2 cups unsalted butter , softened 1 1/2 cups brown sugar 4 large eggs 2 tablespoons coffee extract[...]

4 ounces bittersweet chocolate , chopped (don't use unsweetened or semisweet) 1/2 cup butter , cut into small pieces 1 tablespoon instant espresso powder[...]