Gooey Butter Cake

Preheat oven to 350° and grease a 9"-x-13" baking pan with cooking spray. In a large bowl, combine cake mix, melted butter, and egg. Press into prepared pan. In another large bowl using a hand mixer, beat together cream cheese, melted butter, eggs, vanilla, and a pinch of salt. Add powdered sugar and beat until smooth. Pour over crust and bake until golden and puffed, 40 minutes. Center should still be gooey. Let cool. Sprinkle with more powdered sugar before serving.