Preheat the oven to 350 degrees F and spray the cake pan of your choice with non-stick cooking spray.
In a large mixing bowl, mix the yellow cake mix, 0.25 cup white sugar, 0.5 cup oil, water, 4 eggs, canned pumpkin, and ground cinnamon until well combined (about 2 minutes on medium-high).
Pour the pumpkin cake batter into the prepared pan.
Make the filling by creaming together the softened cream cheese and 0.5 cup sugar. Then add in the 0.25 cup oil and 1 egg. Mix until smooth. Fold in the white chocolate chips.
Drop the cream cheese filling into the cake batter by the spoonful. Allow the filling to sink into the batter. Swirl a knife through the filling a bit to make sure the filling is covered by the batter.
Bake until a toothpick inserted into the center of the cake comes out clean (approximately 40-45 minutes depending on pan size).
Notes
Store any leftover cake in an airtight container in the refrigerator to keep the cream cheese filling fresh.