Cream butter well, and add sugar and milk alternately, a little at a time, stirring until smooth after each addition.
Stir in vanilla.
When smooth, pour over the cake; let stand a few hours, if possible, before cutting.
Sufficient for one 8-inch layer.
This frosting is frequently used on coffee cakes, tea rings, Jule Kake, and plain cakes or cup cakes.
Fruit juice may be used in place of milk and vanilla.