Grease a 9×13 pan and turn oven to 350°F.
Blend cake mix, 1 egg, and butter until smooth. Press into your greased 9×13 pan.
Blend cream cheese, 2 eggs, vanilla and powdered sugar until creamy and smooth. Spread over your the first mixture in your pan.
Bake at 350°F for 40-45 minutes or until edges are golden brown (middle may sink in a bit).