Preheat the oven to 350°F. Spray a 9x13-inch baking dish with cooking spray, set aside.
In a large bowl or the body of a stand mixer with the paddle attachment, add the cake mix, pumpkin puree, milk, eggs, vegetable oil, and brown sugar.
Stir slowly to combine, then place on low speed and mix for 2 minutes.
Pour the batter into the 9x13-inch baking dish, set aside.
In a medium bowl, cream the cream cheese with an electric hand mixer until smooth.
Add the melted butter and stir to combine. Add the powdered sugar 1 cup at a time, and mix it in fully before adding more. Stir in the pumpkin pie spice.
Add dollops of the cream cheese mixture all over the top of the cake batter.
Using a butter knife, swirl the batters together.
Sprinkle the top with the chocolate chips. Bake for 40-45 minutes until a toothpick inserted into the center comes out clean.
Let cool completely on a wire rack. Serve as-is or with ice cream or whipped cream on top.
Notes
Other chocolate chip flavors can be used.
This can be frozen, see above on how to do that.
Chopped nuts can be used in the cake batter for more texture if you want.