This recipe is from my sister Jennifer, who is one of the best bakers I've ever known! She's perfected this recipe and it is amazing. It makes a huge batch, which makes it easy to share.
1 1/4 c. butter, cold
1/2 c. + 2 T. powdered sugar
2 1/4 c. flour
1/8 + a pinch of salt
Mix sugar, flour and salt together and then cut the cold butter into the mixture until you have very fine crumbs. Spread crumbs evenly onto a jelly roll pan (17.5" X 12" cookie sheet with sides) and press the crust down, working your way all around the pan so that it is evenly distributed. Bake the crust in a 350 degree oven for 10-14 minutes, watching very closely so it doesn't burn or get brown. Cool.
4 c. sugar
2/3 c. flour
3/4 c. lemon juice (fresh or bottled)
Mix sugar and flour together. Mix eggs and lemon juice just until combined; don't beat or there will be a foamy surface. Stir dry and liquid ingredients together until combined and very smooth.
Pour filling over cooled crust and bake at 350 degrees for 25-30 minutes, without browning the top. Sides will get brown, but the entire center should stay yellow.
Remove from oven and immediately take a metal spatula, dip it in powdered sugar and pry the edges away from the sides of the pan. Continue dipping the spatula in the powdered sugar as it gets sticky. Dust a very generous amount of powdered sugar over the top of the lemon bars. Let the pan cool completely in the fridge, overnight works well. When it's cool, carefully cut all four sides off and then cut the lemon bars into equal pieces.