Shortbread Lemon Bars

From Taste of Home

1 1/2 c. cups flour
1/2 cup powdered sugar
1 tsp. grated lemon peel
1 tsp. grated orange peel
3/4 c. cold butter or margarine

Filling:
4 eggs
2 cups sugar
1/3 c. lemon juice
1/4 c. flour
2 tsp. grated lemon peel
2 tsp. grated orange peel
1 tsp. baking powder

Topping:
2 cup (16 oz.) sour cream
1/3 c. sugar
1/2 tsp. vanilla extract

In a food processor, combine flour, powdered sugar, and lemon and orange peel.  Cut in butter until crumbly; process until mixture forms a ball.  Pat into a greased casserole dish or cake pan.  Bake at 350 for 12 minutes or until set and the edges are lightly browned.  Meanwhile, in a mixing bowl combine filling ingredients and mix well.  Pour over hot crust.  Bake 14 minutes or until set and lightly browned.  In another bowl, combine topping ingredients.  Spread over filling.  Bake 7 minutes longer or until topping is set.  Cool on a wire rack.  Refrigerate overnight.  Cut into bars just before serving.  Makes about 3 dozen.