Preheat the oven to 350 degrees F. Grease a 9x13 glass baking pan.
In a large mixing bowl combine triple chocolate fudge cake mix with pudding in the mix and the eggs. Add 1 cup water and 1/2 cup vegetable oil. Beat with a whisk until completely smooth, about two minutes.
Pour into the baking pan. Scrap the mixing bowl with a rubber spatula.
In the same bowl, combine room temperature cream cheese and melted butter.
Add pumpkin puree, brown sugar, and nutmeg. Mix it until it’s as smooth as possible, then drop by spoonfuls on top of the prepared cake mix.
Using a butter knife, swirl the cream cheese mixture into the cake mixture. Keep swirling, then swirl some more, if you don’t the pumpkin mixture will sink to the bottom and not combine with the cake.
Bake at 350 for 35-40 minutes, or until a toothpick inserted into the middle comes out clean.
Allow to cool completely on a raised rack before slicing. You can ice the cake if desired, or serve plain.