Kick the tires and light the fires to 325 degrees.
Mix the flour and sugar then cut the butter in.
Add the lemon zest.
Mix completely then press into the bottom of an 8x8 baking pan.
Bake in the oven for 9-12 minutes until the base has browned. Remove and set to the side.
Continue with the filling. Mix the sugar, baking soda and flour together.
Whip the eggs, one yolk and whipping cream in a bowl, add the lemon juice and rind, then add the dry ingredients in.
Pour the filling on the crust. Bake in a 325 degree oven until the middle is set. The lower temperature makes the top end up a lot less brown, as most recipes tell you at the end to cover the too-browned top with icing sugar.
Notes
This bar freezes well, just slice and place in an airtight container and freeze.