In medium mixing bowl combine flour, butter and sugar with fork until crumbly. Press into ungreased 9 x 13 baking dish. Bake for 20 minutes or until slightly golden brown. While crust is baking beat cream cheese and powdered sugar until smooth. When crust is done baking throw it in the fridge for about 30 minutes to cool it off quickly. When it is cool to the touch spread cream cheese mixture over crust, next the pie filling and top Dream Whip prepared according to package.