Preheat oven to 350°F (325°F if using a dark pan). Grease a 9×13 inch baking pan with cooking spray.
Using an electric mixer, combine the cake mix, 2 eggs, and melted butter. The batter will be thick. Spread into the bottom of the greased pan with a rubber spatula.
Reuse the bowl (no need to clean) to combine the cream cheese, 2 eggs, powdered sugar, and vanilla until smooth. Pour over the top of the cake batter.