1 c. all-purpose flour
1/2 c. butter, softened
1/4 c. powdered sugar
1 c. granulated sugar
2 eggs
2 tbsp. all-purpose flour
2 tsp. grated lime peel
2 tbsp. lime juice
1/2 tsp. baking powder
1/4 tsp. salt
2 or 3 drops green food color

Heat oven to 350 degrees. Mix flour, butter, and powdered sugar. Press in ungreased square pan, 8 x 8 x 2 or 9 x 9 x 2 inches, building up 1/2-inch edges. Bake 20 minutes.

Beat remaining ingredients until light and fluffy, about 3 minutes; pour over baked layer. Bake until no indentation remains when touched in center, about 25 minutes.

Cool; sprinkle with powdered sugar if desired. Cut into 1-inch squares. About 4 dozen squares.