Blend dry cake mix, butter and 1 egg. Press into a greased 13x9 pan.
Beat cream cheese until smooth. Gradually blend in powder sugar. Stir in lemon juice and peel until smooth. Reserve 1/2 cup and refrigerate it. Beat 2 eggs into remaining or un-reserved cream cheese mixutre until blended.
Spread over cake mixture. Bake at 350 until set, around 25 mins. Cool completely. Spread with reserved cream cheese mixture. Refrigerate until firm.