Ingredients for Cake
2-3/4 cups flour
3 tsps baking powder
1 tsp salt
2/3 cup butter
1-1/2 cup sugar
3/4 cup champagne
6 egg whites
Ingredients for Frosting
1 cup softened butter
9 to 9-1/2 cups powdered sugar
1/4 cup milk
1/4 cup champagne
1 tbsp vanilla
Grease a 10-inch round cake pan. Cream together butter and sugar until very light and fluffy. Sift together flour, baking powder, and salt. Stir dry ingredients into butter mixture alternately with champagne.
Beat egg whites until stiff peaks form. Fold 1/3 of the egg whites into batter, then fold in remaining whites. Pour batter into cake pan. Bake at 350 F for 25-30 minutes, or until a toothpick inserted in the center comes out clean.
While the cake is baking, prepare the frosting: Beat butter for 30 seconds. Gradually add 4 cups powdered sugar. Beat in milk, champagne and vanilla. Beat in remaining cups powered sugar (adding a little at a time) until frosting reaches spreadable consistency.
Frost cake when it is completely cooled and decorate with frosting or candy bubbles.