1. Heat oven to 375 degrees F. Line 20 muffin cups with paper liners. Sift together flour, baking powder and salt onto waxed paper.
2. Beat sugar, butter, eggs and 1/4 cup milk in bowl at medium speed until light and fluffy, 3 minutes. Alternately, in 3 additions, beat in flour mixture and remaining milk. Spoon scant 1/4 cup of batter into each liner.
3. Bake in 375 degree oven 20 minutes or until golden brown and wooden pick tests clean. Remove to racks to cool.Prepare frosting:
4. Beat together butter, orange rind, juice, salt and sugar in bowl until smooth and creamy. Tint with food coloring if desired. Use to frost cupcakes.