Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the cake mix, pumpkin puree, eggs, milk, and vanilla extract.
Pour the batter into a greased 9x13 inch baking pan.
In a separate bowl, beat the softened cream cheese and powdered sugar until smooth.
Drop spoonfuls of the cream cheese mixture over the cake batter and gently swirl with a knife.
Sprinkle pumpkin pie spice over the top of the cake.
Bake for 35-40 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool before serving.
