Perfecting the lemon bar

I was on a quest this weekend to create a good tasting GFCF lemon bar. I started with a standard recipe from a recipe book and just substituted GFCF flour and it was pretty blah. It was too sweet and not sour at all. I want to taste lemon in a lemon bar. So I decreased the sugar and increased the lemon juice and added some lemon oil (available from speciality retailers) and it wasn't bad. I'll probably still tweak it some - maybe more lemon and/or less sugar again.

Here's the recipe as it stands now:

GFCF Lemon Squares

1 cup GF flour (I use Bob’s Red Mill GF Mix)
½ CF margarine (I use Crystal Farms Dairy Free)
¼ Powdered Sugar
¼ teaspoon lemon oil (optional)
2 eggs
¾ cup granulated sugar
½ teaspoon baking powder
¼ teaspoon salt
¼ cup lemon juice
¼ teaspoon lemon oil (optional)

Heat oven to 350 degrees. Mix thoroughly flour, margarine and powdered sugar. Press in ungreased square pan, 8x8x2 building up a slight edge. Bake 20 minutes

Beat remaining ingredients about 3 minutes or until light and fluffy. Pour over hot crust. Bake about 25 minutes longer or just until no imprint remains when touched lightly in center. Cool and cut into squares. Makes 16 squares.