Preheat your oven to 350°F (175°C).
Grease a 9×13 inch baking dish with non-stick spray or butter.
In a mixing bowl, combine the yellow cake mix and half of the melted butter. Press this mixture into the bottom of your prepared baking dish.
In another bowl, mix the softened cream cheese with the remaining melted butter and the powdered sugar until smooth. Add in the pumpkin puree, vanilla extract, eggs, and pumpkin pie spice. Whisk until combined.
Pour the gooey filling over the cake base and bake for approximately 40-45 minutes.
Allow the cake to cool for at least 30 minutes before serving.