Crust:
1 cup butter
2 cups flour
1/2 cup powdered sugar
Mix together well and pat into the bottom of a 9 x 13 pan or a jelly roll pan. Bake crust at 350 for 15-20 minutes until slightly tan in color.
Key Lime Filling:
4 eggs, separate whites and yolks
1 1/2 cups sugar, halved
4 TB flour, halved
1/4 cup of key lime juice (fresh is best, but bottled is fine too)
1 tsp baking powder
Beat the eggs whites with half of the flour and half of the sugar. Beat until stiff. Beat the egg yolks with the other half of the flour and sugar, and also add the baking powder and lime juice. Fold yolk mixture into egg white mixture. Pour over crust and bake at 350 for 25 minutes.
Find it online: https://makinglifeblissful.com/2020/08/key-lime-bars-recipe.html