Preheat oven to 350°F. Spray a 9x13 cake pan with non-stick spray or line it with foil.
In a large mixing bowl, mix cake mix, melted butter, and eggs with a sturdy spoon until well blended. (It will be thick like a cookie dough.)
Use your fingers or a bench scraper to press dough into the prepared pan.
Make cream cheese topping: In a mixing bowl, beat cream cheese and two cups of powdered sugar on low speed until smooth. Add eggs and vanilla and beat on low speed until blended. Add remaining 1 ½ cups powdered sugar and beat until blended. Pour over cake bottom and spread to the edges of the pan.
Bake for 35 to 40 minutes or until topping is set and golden brown and it’s pulling away from the sides of the pan. Cool completely in the pan.
To serve, cut into squares and sprinkle top with additional powdered sugar if desired.