1 2/3 c. flour
1/3 c. powdered sugar
1 c. butter, softened
1 tsp. vanilla

In medium bowl combine first 4 ingredients; blend well. Chill dough. Heat oven to 350 degrees. Shape dough into 1" balls. Place 2" apart on ungreased cookie sheet. With thumb or finger make imprint in center of each. Bake 8 to 10 minutes or until lightly browned. Remove immediately, cool.

FILLING:

1 egg, beaten
2/3 c. sugar
2-3 tsp. grated lemon peel
1 tsp. cornstarch
1/4 tsp. salt
1 tbsp. butter coconut or powdered sugar or both

In saucepan combine ingredients except coconut or powdered sugar. Cook over low heat stirring constantly until thickened. Cool. Top each cookie with filling. Sprinkle with coconut or powdered sugar.