Tart Lemon Frosting

I put this frosting on lemon cake or cupcakes, or vanilla cake.

Ingredients:
1 teaspoon grated lemon rind
4 tablespoons butter
3 cups of icing (confectioner's) sugar, sifted
3 tablespoons lemon juice
1 dash salt

Preparation:
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.

This recipe is from the Recipe Goldmine website.