I love lemon bars and I make them all the time - this recipe is easy to do and doesn't actually require a mixer - its just easier with one. I made these when I was living in Rome a few times, because Italian lemons are about twice the size of normal lemons and squeezing out the juice was really easy. Overall, for something made from scratch, these are totally worth the work - brownies are not.
1 c all-purpose flour
1/2 c butter or stick margarine, softened
1/4 c powdered sugar
1 c granulated sugar
2 tsp grated lemon peel (optional)
2 tbsp lemon juice
1/2 tsp baking powder
1/4 tsp salt
2 large eggs
1 mixing bowl
1 8x8 or 9x9 pan
1) Heat oven to 350F
2) Mix flour, butter, and 1/4 c powdered sugar. Press in ungreased square pan, 8x8x2 or 9x9x2 inches, building up 1/2 inch edges.
3) Bake crust 20 minutes; remove from oven.
4) Beat remaining ingredients except powdered sugar with electric mixer on high speed about 3 minutes or until light and fluffy. Pour over hot crust.
5) Bake 25-30 minutes or until no indentation remains when touched lightly in center. Cool in pan on wire rack. Dust with powdered sugar. For bars, cut into 5x5 rows.