1 pkg. Pillsbury lemon cake mix plus pudding
1/2 c. butter, softened
1/4 c. firmly packed brown sugar
1/2 tsp. cinnamon
1 c. sour cream
1 egg

Heat oven to 350 degrees. Combine first two ingredients; mix well until crumbly. Reserve 2/3 cup for topping. Add brown sugar and cinnamon to reserved topping mix. Mix well. Set aside.

Press remaining mixture onto bottom of ungreased 9x13 inch pan.

Blend sour cream and egg; spread evenly over mixture in pan. Sprinkle reserved topping mixture over all. Bake at 350 degrees for 25-30 minutes or until topping is golden brown and bubbly. Makes 12-15 squares. Refrigerate leftovers.