Preheat oven to 325°F. Grease a 15x10 inch jelly roll pan with cooking spray.
In a large bowl, whisk together the eggs, sugar, pumpkin purée, and melted butter.
In another large bowl, whisk together the flour, baking powder, baking soda, salt, and pumpkin pie spice.
Fold the flour mixture into the pumpkin mixture just until combined.
Pour the mixture into the prepared pan. Bake for 28–30 minutes, or until a toothpick inserted into the center of the bars comes out clean.
Let cool completely.
For the frosting:
Place the softened cream cheese and softened butter in a large bowl. Mix with a handheld mixer until light and fluffy.
Add the vanilla and powdered sugar. Mix until a smooth frosting forms.
Spread the frosting over the cooled cake.
Refrigerate for 1 hour before slicing (for the cleanest cuts), or until you’re ready to serve it.
Video
Notes
Use a jelly roll pan: This recipe is made in a jelly roll pan (10x15 inches). If you don't have one, you can halve the recipe and use a 9x13 inch pan.How to store and serve: Store in the fridge, but serve at room temperature. Refrigerate for 1 hour before slicing (for the cleanest cuts).Don't have pumpkin pie spice? You can make your own by combining 1½ teaspoons cinnamon, ¼ teaspoon ground ginger, ¼ teaspoon ground nutmeg, a pinch of allspice, and a pinch of cloves.Freezing instructions: Freeze for up to 3 months by covering tightly with a layer of plastic wrap and then an additional layer of foil. It is easiest to freeze the cake before it is frosted. Allow it to thaw overnight the day before you plan to serve it. Then, prepare the frosting, and spread it on the cake just before you need it. You can also freeze individual bars in an airtight container.