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.
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.
