WHIPPED COCOA FROSTING

1 envelope (1.3 ounces) dry whipped topping mix
1/2 cup cold evaporated skimmed milk
2 tablespoons unsweetened cocoa
1/2 teaspoon vanilla

Combine ingredients in a small bowl. Beat on high speed with an electric mixer for 3 to 4 minutes or until the mixture stiffens and soft peaks form. Makes 2 cups. Refrigerate cake after frosting.