I've made these so many times, I could do them without the recipe and with my eyes closed. Everytime we would go to a picnic or a church dinner, these or my brownies would be requested...so I complied. It would actually upset me, cuz I can and do make so many other things, some spectacular things, and they would request 'Lemon Bars'...OK, I'll give them lemon bars....no I'll give them the BEST LEMON BARS EVER!
*This is what chefs call an "ABC" crust.
Sift together, into a good size bowl, the powdered sugar and the flour. Add the zest and stir it in with a wire whisk to mix it well.
Make a well, and stir in the melted butter. Mix until dough forms. I usually use a spoon to stir in the butter, and making it into the dough.
Press dough into the bottom of a 9 x 13 inch baking pan.
Place in a pre-heated 350F degree oven and bake until light brown, about 15-20 minutes. When light brown, remove from oven and set aside, for 10 minutes only.
While crust is baking, prepare Filling.
Into the bowl of a stand mixer, with the paddle attachment, (Hand held mixer works just fine as well, just have all ingredients out, measured into seperate bowls), beat 4 Lg eggs, very well, about 3-4 minutes, so when you turn off mixer, eggs have no seperation. With mixer on low add 2 cups Sugar and cream well, raise speed and beat about 2-3 minutes. Scrape sides and bottom and beat an additional 1 minute.
In a small bowl, mix together flour and baking powder, set aside.
With mixer on low, add Lemon juice, (Fresh is best but bottled is fine if that's what avail.) and lemon zest, mix well, add flour mixture** and mix well. Scrape sides and bottom with a rubber scraper, mix for 1 minute more.
Pour filling mixture on still hot, baked crust. Return pan to oven and bake for 40-45 minutes.
Remove from oven and dust top with powdered sugar.
Cool completely before cutting and or Eating. Sugar stays hot for awhile.
Notes: **When adding the baking powder/flour mixture, the baking powder will react with the lemon juice and foam just a bit. That will stop as its mixed in.