Creamy Lemon Squares

20 Nilla Wafers Crushed
1/2 C Flour
1/4 C Brown Sugar
1/4 C Cold Margarine
8 oz. Cream Cheese Softened
1 C Sugar
2 Eggs
2 Tbsp. Flour
3 Tbsp. Lemon Zest Divided
1/4 C Lemon Juice
1/4 Baking Powder
2 tsp.  Powdered Sugar

Heat oven to 350 and line 8" pan with foil.  Mix wafer crumbs, 1/2 C flour and brown sugar.  Cut in margarine with pasry blender or 2 knives until mix resembles coarse crumbs.  Press on bottom of prepared pan and bake 15 minutes.
Beat cream cheese with sugar until blended.  Add eggs and 2 Tbsp. flour.  Mix well then blend in 1 Tbsp lemon zest, juice, and baking powder.  Pour over crust.
Bake 25-28 minutes or until center is set.  Cool and refidgerate at least 2 hours.  Sprinkle with powdered sugar and remaining lemon zest.  Use foil to lift dessert from pan before cutting.