Beat together butter and sugar until creamy and smooth. Beat in egg, lemon juice and rind. (The mixture may look curdled.) Stir in flour, baking powder and salt. Place crushed flakes in a plate (should be about 1-1/4 cups). Drop cookie batter by teaspoonfuls on crushed flakes and toss to coat. Place on ungreased cookie sheet. Bake in 350 degree oven 15 minutes. Cool on rack.
Reprinted with permission from: Powdered Sugar Cookies from the C and H Sugar Kitchen by Jean Porter