I can help you out, but I think you'll find that the recipe for Butter Cream and Butter Icing are very close.

BUTTER ICING

3 cups sifted confectioner's sugar
1/3 cup soft butter
3 Tbsp. cream
1 1/2 tsp. vanilla

Blend together the sugar and butter until creamy. Add the cream and vanilla and stir until smooth and blended.

Or are you perhaps thinking of a cooked type icing?