Sift together flour and confectioners sugar.
Cut in butter until mixture clings together. (I use my hands to mix in the butter to the mix - it gets messy but is the best way to get it in there!)
Lay down a piece of parchment paper in a 9x13" pan. Press crust mix into 9x13" pan.
Bake @ 350 for 20-25 minutes, or lightly browned and then cool.
In a bowl, mix cream cheese until smooth.
Add 1 egg and vanilla and beat well. Set aside.
In a separate bowl, beat 4 eggs until frothy.
Add granulated sugar and lemon juice.
Sift together 1/4 cup flour and baking powder and stir in to egg mixture.
Spread cream cheese mixture over cooled crust.
Cover with egg mixture. (Pour this slowly, do not dump it onto the layer, it will not layer well)
Bake for 25 minutes, or until done. (might need longer depending on thickness of bars)
Sprinkle with powdered sugar and cut into squares.