Mix flour, butter, and powdered sugar in a medium bowl - mixture will be crumbly. Press into an ungreased 9x13 baking dish (I prefer glass), building up the edges slightly. Bake crust for 20 minutes at 350°. Remove from oven and set aside.
When crust has about 5 minutes left, add remaining ingredients (except the powdered sugar for sprinkling) to a separate medium bowl. Beat with an electric mixer on high for about 3 minutes, or until light and frothy. Pour over hot crust.
Bake 30 minutes, or until middle is set; lemon bars will be light brown on top and should not look liquidy in the middle.
Cool completely in pan. Cut into squares and then sprinkle with a dusting of powdered sugar.
Recipe by Food Fun Family at https://foodfunfamily.com/classic-lemon-bars/