Tart Lemon Frosting

1 teaspoon grated lemon rind
4 tablespoons butter
3 cups confectioners' sugar, sifted
3 tablespoons lemon juice
1 dash salt

Add lemon rind to butter; cream well. Add part of sugar gradually, blending after each addition. Add remaining sugar alternately with lemon juice, until of right consistency to spread, beating thoroughly after each addition. Add salt.

Makes enough frosting to cover the top of one layer and sides of three 9-inch layers.