Frosting: Beat sugar, melted butter and lemon juice in a small bowl until smooth.

Cookies: Preheat oven to moderate (350°F). Grease cookie sheets. Cream butter with sugar. Add flour sifted with cornstarch and salt. Mix in the lemon rind. Shape into 1-inch balls and roll in the chopped nuts, pressing them in. Bake about 15 minutes. Cool on wire rack. Drizzle with Lemon Frosting.