1Heat oven to 325. Cut butter into flour and confectioners' sugar with a pastry knife. Add lemon zest and mix in well using fingers.
2Pat crust into an ungreased 13x9 pan. Bake for 18-20 min.
3While crust is baking, prepare lemon filling.
4Whisk 4 eggs with sugar until well blended. Add flour, lemon juice and lemon juice. Mix well. Add lemon curd and mix until well blended.
5Pour lemon filling over hot short bread crust and return to the oven for 20-22 min.
Loosen around edges, allow to cool slightly and cut into bars. When cooled completely dust with confectioners' sugar.