Preheat oven to 350 degrees. Grease a 9 x 13 - inch baking pan. Mix flour and butter; spread in pan. Bake for 20-25 minutes or until golden. Let crust cool.
Mix cream cheese, powdered sugar, Lemon pie filling, vanilla, and half of the whipped topping together. Spread remaining whipped topping over pie filling mixture.
Cover and chill until ready to serve.
Garnish with lemon slices.
Recipe by The Gingham Apron at https://www.theginghamapron.com/happy-mothers-day-a-lemon-dessert/