1Preheat oven to 350F degrees.
Spray a 9x13 baking pan with nonstick cooking spray
2Start making the crust.
In a medium bowl, combine cake mix, melted butter and egg.
Beat together using an electric or stand mixer on low for 2 minutes.
You'll notice the batter will start to pull away from the sides of the bowl
3Spread the batter into the bottom of your baking dish.
It's best just to get in there with your hands to get it all evenly spread out
4Now make the filling.
Using the same mixing bowl, add the cream cheese and beat on low until smooth.
Add the eggs, melted butter and vanilla extract and mix on medium speed for 1 minute.
Add in the confectioners sugar and mix everything together until smooth and well incorporated
5Place 1 cup chocolate chips into a microwave safe bowl or dish.
Microwave chips on high for about 1 minute (maybe longer depending on your microwave).
6Stir chips to make sure they all melted.
7Combine cream cheese filling with melted chocolate.
8Whisk together until well blended and all one color
9Pour vanilla cream cheese filling on top of crust and spread out evenly.
10Using a spoon, dollop chocolate filling on top of cream cheese filling.
11Using a butter knife, swirl the knife around so the top of the batter has a marbled effect.
Be careful not to cut through the crust.
12Bake for about 45 minutes. Be careful not to overbake.
Remember, this is gooey butter cake so you want that filling to stay a little soft