Step 1

Using a pastry cutter or in a food processor blend together the butter sugar and flour.

Step 2

Press evenly into the bottom of a greased and parchment paper lined 9×13 inch baking pan.

Step 3

Bake for 20 to minutes at 350 degrees F ( 325 degrees F if you are using glass bake-ware) The bottom should just be beginning to brown slightly at the top edges.

Step 4

Simply whisk together the sugar flour, eggs, zest and lemon juice until the sugar is dissolved.

Step 5

Allow the topping to sit for about 10 minutes before whisking together well again and pouring over the baked shortbread base.

Step 6

Bake at 350 degrees F for about another 20- 25 minutes or until the top is slightly browned and the custard appears to be set. Cool completely. Sprinkle with icing sugar when cool or try adding a meringue topping.