Butter Crisps

3/4 cup unsalted butter, at room temperature 1 cup granulated sugar 3 egg yolks 1 1/2 teaspoons grated lemon rind 1 1/2 teaspoons lemon juice 1 1/2 teaspoons cherry liqueur (kirsch) 1/8 teaspoon salt 2 cups all-purpose flour colored sugar...