Cut butter in until the butter is completely incorporated into the dry ingredients.
Press half the crumb mixture into a 9 x 13 well greased pan.
Pour lemon filling ( commercial or homw made ) over the bottom crumbs.
Gently sprinkle the remaining crumbs over the lemon filling.
Bake for 30 - 35 minutes or until light golden brown.
Cool completely in pan before cutting into squares
1/3 cup corn starch.
1/3 cup cake flour.
pinch of salt.
1 1/2 cups of sugar.
5 egg yolks, slightly beaten.
Zest of 2 large lemons.
Juice of 2 large lemons.
2 cups water.
2 tablespoons of butter.
In a medium sauce pan, combine corn starch, cake flour, sugar and salt. Pour in water and stir constantly over medium low heat until mixture comes to a slow boil. Remove the pan from the heat and reduce heat to low. Pour about a cup of this mixture onto the slightly beaten egg yolks while whiosking constantly. Pour the egg mixture back into the other mixture, whisking constantly. Return to the stove and cook for an additional 3 minutes, stirring constnatly. remove from heat and stir in lemon juice and lemon rind. Whisk in butter, one tablespoon at a time.