Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking pan.

In a mixing bowl, combine the yellow cake mix, 2 eggs, and melted butter until well blended and crumbly. Press evenly into the bottom of the pan.

In another bowl, beat the softened cream cheese until creamy. Add pumpkin puree, remaining 2 eggs, vanilla extract, pumpkin pie spice, and ground cinnamon, and mix until smooth.

Gradually add the powdered sugar, mixing well after each addition to create a fluffy filling.

Pour the filling over the base, spreading it evenly with a spatula or spoon.

Bake for 35-40 minutes until the top is set and lightly crackled.

Allow the bars to cool completely in the pan for at least 30 minutes before slicing.

Cut into squares or rectangles and serve at room temperature or warm.