Crust: Combine flour, powdered sugar and butter to form the bottom layer crust. Use a hand mixer until butter is completely broken up, and looks like crumbs. Let sit for an hour, so butter absorbs into flour. (Try with melted butter, then put in fridge and break up with pastry cutter)

Spread into a 13 x 9” baking
pan. Mixture will be crumbly, it will bake down as the butter melts. You can pat it down lightly, especially in the corners, but not too heavily or it will be hard as a rock. Bake at 350° (375° on convection) for 20 minutes (until golden brown).
Remove and let cool while you make the filling

Filling: Beat eggs. Combine with sugar, flour, baking powder and lemon juice, mix until fluffy. Add lemon rind and stir in (or it gets stuck in the beater blades). Pour over baked crust. Bake at 350° another 25 minutes, until top starts turning golden brown and center is not jiggly. Internal temperature of filling of 200-210° F.?

Remove from oven. Sprinkle with powdered sugar. Cut into squares when cool.