In a bowl, mix together the cake mix, one egg and butter. Press into the bottom of an 8 ½ x 11-inch greased pan. In the bowl of an electric mixer, combine four eggs, extra fine sugar and cream cheese.
Preheat oven to 350 degrees. For the top layer: Sift the cake mix into a bowl. Add butter, lemon zest and egg. Spread evenly on the bottom of a greased 9" x 9" pan. In the bowl of an electric mixer, ...