Preheat oven to 400°F. Liberally spray a sheet pan with nonstick spray and set aside.
To a large bowl, add all ingredients (except any desired toppings). Whisk until just combined (it's okay if it's still a little lumpy), then pour into the prepared sheet pan. Use a rubber spatula to spread batter evenly over the pan.
2.5 cups pancake mix, 1.5 cups milk, 1 cup pumpkin puree, 2 large eggs, 1/4 cup light brown sugar, 1 tablespoon vanilla bean paste, 1 tablespoon pumpkin pie spice
If you're adding toppings, sprinkle them over the top of the batter now.
optional toppings
Place sheet pan in the oven and bake for 15 minutes. The sheet pan pancakes are done when you gently press on them in the center and they bounce back/ don't stay indented.
Let cool a few minutes, then slice, serve, and enjoy!