Preheat the oven to 300 degrees Fahrenheit and spray a 9"×13" baking dish with cooking spray.
In the bowl of an electric mixer, mix cake mix, melted butter, vanilla extract and one egg to form a soft dough.
Press/spread dough evenly into the bottom of the greased pan.
Mix powdered sugar, softened cream cheese and remaining two eggs until smooth, about 1-2 minutes, scraping down the sides with a spatula in between.
Pour on top of crust. Bake for 35 to 45 minutes, or just until set. Mine were done in 37 minutes. The top will get crackly and poofy and then settle down as it cools.
Allow it to cool completely at room temperature, then slice and serve with a scoop of vanilla ice cream on each piece.