Preheat oven to 350°F and line the bottom and sides of a 9x13 pan with parchment paper.

In a mixing bowl, combine the cake mix, melted butter, pumpkin pie spice, and chopped pecans.

Press about half of the mixture into the bottom of the pan and set aside the remainder.

In another bowl, stir the cream cheese until smooth. Add the sweetened condensed milk, egg, and vanilla and whisk until smooth; set aside.

In a separate bowl, combine all ingredients for the pumpkin layer. Whisk until smooth and set aside.

Scoop the cream cheese filling and pumpkin filling over the crust, alternating to create a marbled look.

Sprinkle the remaining crust mixture over the top of the fillings.

Bake for 35-40 minutes, or until the bars don't move when jiggled.

Let cool to room temperature then refrigerate until ready to serve.