I've used a variation on the Neiman Marcus Cake as Lemon Bars.

For the bottom: 1 lemon cake mix, 1 stick of margarine, 1 cup of pecans chopped,and 1 egg slightly beaten.

For the topping 1 lb powdered sugar, 2 eggs (beaten until fluffy), 8 oz of cream cheese.

Bake at 350 for about 30-40 minutes until browned on top. Check topping to make sure it is not real runny. 40 minutes seemed about right for my oven, but you know how that goes.