Creamy Lemon Cake Bars

From Simple and Delicious Magazine

1 pkg (18 1/4 oz) lemon cake mix
1/2 cup butter, softened
1 egg

Filling:
1 can (16 oz) lemon frosting
1 pkg (8 oz) cream cheese, softened
2 eggs

Beat cake mix, butter, and egg in a large bowl until crumbly. Press into the bottom of a greased 13x9 baking pan.

Beat frosting and cream cheese in another bowl until smooth. Set aside 1/2 cup for topping. Add eggs to remaining mixture; beat on low speed until combined. Spread over crust.

Bake at 350 degrees for 35-40 minutes or until filling is set. Cool on a wire rack for 1 hour. Spread reserved frosting mixture over top. Refrigerate for at least 2 hours. Cut into bars. Store in the refrigerator.