Add eggs to large mixing bowl, and beat with mixer until slightly foamy
Mix in the sugar, 1 cup at a time, then add flour, and mix well
Add lemon juice and zest, and mix thoroughly
Remove crust from oven, and pour filling evenly over warm crust
Bake for 20 to 25 minutes or until top is set and springs back lightly when touched. Don't let the top get too brown
Remove from oven, and run a knife or spatula around the edges of crust while still warm. Sprinkle sifted powdered sugar lightly over crust, if desired, and allow to cool
For best results, refrigerate for at least 1 hour before cutting into bars. Keep refrigerated until ready to serve. Add additional powdered sugar, if desired, before serving