Ingredients for the Shortbread base:
1 1/2 cups of flour
¾ cup of butter
1/4 cup of powdered sugar
¼ cup of granulated sugar
Directions for the shortbread base:
Heat the oven to 350ºF.
Mix the flour, butter and sugars using an electric mixer on medium speed. A dough will form and then it is done mixing. Press the mixture into a lightly buttered rectangular glass baking dish, 9x13x2 inches. Bake for 20 minutes. Put the baking dish on a wooden cutting board.
Ingredients for the Lemon topping:
1 1/2 cups of granulated sugar
6 tablespoons of fresh lemon juice (two good size or three regular lemons)
3 teaspoons of grated lemon zest
3/4 teaspoon of baking powder
¼ teaspoon of salt
3 eggs
Directions for the Lemon topping:
Beat the all of the lemon topping ingredients using an electric mixer on medium and then medium high speed until the mixture is light and fluffy.
Once the lemon topping mixture is made, immediately pour it over the top of the shortbread mixture, spread it evenly with a knife and bake for 25 minutes at 350ºF.
Put the baking dish on a wood cutting board.
Allow the lemon squares to cool completely to room temperature. Cut the final product into squares about 1½ inch by 1½ inch. Dust the tops with powdered sugar.