1 cup butter or margarine, cut in chunks
2 cups flour
1/2 cup sugar
1/4 to 1/3 cup lemon juice (preferably fresh, but bottled is also fine)
2 cups sugar
1/4 cup flour
1 tsp baking powder
Preheat oven to 350 F.
For base: Process base ingredients on the Steel Blade of a food processor until crumbly, about 20 seconds. Press into sprayed 9 x 13-inch baking pan. Bake for 18 to 20 minutes, until golden.
For topping: Process topping ingredients until blended, about 10 seconds. Pour over base. Bake 25 to 30 minutes longer, until golden. Cut into squares when cool.