1. Heat oven to 350°F. Grease and flour muffin cups (2-1/2 inches in diameter) or line with paper bake cups.
2. Combine dry ingredients in large bowl. Add eggs, buttermilk, water, oil and vanilla; beat on medium speed of mixer 2 minutes (batter will be thin). Fill cups 2/3 full with batter.
3. Bake 15 minutes or until wooden pick inserted in centers comes out clean. Remove cupcakes from pan. Cool completely. To make chocolate stars for garnish, if desired, cut several cupcakes into 1/2- inch slices; cut out star shapes from cake slices. Frost remaining cupcakes with VANILLA FROSTING. Garnish with chocolate stars or with red and blue decorating icing. About 30 cupcakes.
* To sour milk: Use 1 tablespoon white vinegar plus milk to equal 1 cup.
VANILLA FROSTING: Beat 1/4 cup (1/2 stick) softened butter, 1/4 cup shortening and 2 teaspoons vanilla extract in large bowl. Add 1 cup powdered sugar; beat until creamy. Add 3 cups powdered sugar alternately with 3 to 4 tablespoons milk, beating to spreading consistency. About 2-1/3 cups.