Preheat oven to 350 degrees. Combine softened butter, 1 cup of flour and 1/4 cup of sugar for crust. Do not overmix. Press into an 8x8 glass baking dish for crust. Bake 12 minutes or until pale but dry. Do not overtake, crust will complete baking later. While crust is baking, make lemon filling with remainder of ingredients, except powdered sugar. Mix well. Pour mixture over partially baked crust. Complete baking at 350 degrees for 15-18 minutes or until Lemon Mixture is done. ( press lightly with your finger, if no fingerprint remains, the Lemon Squares are done. Sprinkle with powdered sugar and continue to cool. Dust again with powdered sugar.
When ready to serve, for parties, cut into small squares. As a dessert, larger squares may be preferred. * Serving suggestion: When ready to serve, top with additional lemon zest for a pretty presentation and a tart fresh taste.