Preheat the oven In a bowl with an electric mixer, mix together the cake mix, egg and melted butter.
Pour the mixture into a greased square or rectangular pan. Firmly press down with a spatula until smooth and even
In that same bowl (which should be clean because the previous crust mixture should have formed somewhat of a solid mass) beat the cream cheese until light and smooth.
Then add the eggs, vanilla, and butter. Blend well.
Lastly, add the confectioners sugar and blend on high for about 2 minutes.
Pour the cream cheese mixture over the crust and bake for 40-50 minutes. (I baked closer to 50 and I regret it. I was afraid of under-cooking it too much but don't be! that's the point!) Next time I will only bake for 40.
Let it cool completely and sprinkle gently with confectioners sugar
Recipe by A Sue Chef at http://www.asuechef.com/ooey-gooey-butter-cake/