Place room temperature butter in a mixing bowl.
Add flour, powdered sugar, salt, vanilla extract.
Mash together until it looks like cookie dough.
Place dough into an oiled pan. Pat down lightly into an even layer.
Take a fork and poke holes throughout.
Bake at 350 F for 22 minutes.
Mix together 2 large eggs plus a third egg yoke – save the egg white on the side.
Add in sugar and flour. Mix together.
Then add in lemon juice & lemon zest, mix again.
Pour onto the shortbread base.
Place back in oven at 350 F for 25 minutes.
Let cool completely before cutting. Then cut into 3 inch x 3 inch squares.
Dust with confectioner’s sugar on top.
Whip remaining egg white and 1 tbsp. sugar into a merengue.
Place on top of squares. Heat with blow torch for a beautiful light browning on top.