I bake like my mother, sister, and grandmothers...I use a recipe as a suggestion sheet. I follow it for the most part, but I like to change it here and there. It's fun.
2 sticks (1 c.) butter, softened
2 c. flour (you could use 1/2 c. less, I'm going to try that next time)
1/2 c. powdered sugar
lemon zest, optional
2 c. sugar (more if you increase lemon juice; I used ~2-1/2 c.)
4 Tb fresh lemon juice (I used the juice from two lemons=7 Tbs)
1 tsp almond extract, optional
4 Tb flour (more if you increase lemon juice; I used generous Tbs)
1 tsp baking powder
Preheat oven to 350°. Combine crust ingredients until crumbly; press into a 10x15-in glass pan or a jellyroll pan. Bake for 20-25 minutes; I pulled mine out after 19 minutes. While crust is baking; beat eggs. Add rest of ingredients. I actually beat the eggs and the sugar by themselves for awhile to dissolve the sugar. Pour lemon mixture over baked crust; return to oven and bake for 20-25 minutes. Apparently the top scorches easily, so you should keep an eye on it. I pulled mine out a couple minutes early. The top formed a crust of sorts; it reminded me of an angel food cake top. I let the bars cool for 30 minutes before cutting, but I probably should have waited longer. They didn't cut "pretty" but that didn't bother me. They were delicious.
Notes: If you don't like how the top looks, you could always sprinkle the bars with powdered sugar. The extra beating of the eggs and sugar made a fluffy lemon layer that I really enjoyed. I didn't really notice the lemon zest in the crust, but it didn't hurt anything.