Cooked Chocolate Frosting

Whisk 1 cup milk, 3 tablespoons flour, and 1⁄8 teaspoon salt in a small saucepan over medium heat until the mixture thickens and begins to bubble -- 1 to 2 minutes. Transfer to a small bowl and let cool.

Melt 8 ounces of either 62 percent dark chocolate or white chocolate. Set aside to cool.

Beat 1 cup butter, 1 1/2 cups confectioners' sugar, and 2 tablespoons cocoa (for white chocolate frosting, omit cocoa) together until light and fluffy. Beat in the cooled chocolate and add milk mixture and 1 teaspoon vanilla extract (dark chocolate frosting only) until smooth and fluffy. Use immediately.