Preheat your waffle iron to medium heat (level 3 to 4). Preheat the oven to 175°F, if not serving right away.
In a large bowl, whisk together the pumpkin puree, milk, sugar, eggs, melted butter, and vanilla. Add the flour, baking powder, cinnamon, and pumpkin pie spice. Stir in chocolate chips, if desired. Be careful not to overmix.
In the waffle mold, pour about 1/2 cup batter. Cook about 2 minutes, or until the waffle iron beeps. Place in warm oven if not serving right away.
Serve warm with butter, syrup, and whipped cream.
Notes
To keep warm: Place on a baking sheet in the oven at 175°F to keep warm.
Beating egg whites: I updated the recipe to remove this step. If you want to make your waffles a little lighter and softer (not as crispy), separate the eggs and beat the egg whites 1 to 2 minutes, or until stiff. Then add in with egg yolks.
Storage: Store leftovers in a zip-top bag or covered container in fridge for 2 to 3 days.
Freezing: Let cool, then place in a freezer bag. Store in freezer for up to 3 months.
To reheat: Reheat in the microwave or toaster oven for 30 seconds, or until warm throughout. You can also place in the oven at 250°F for 5 to 10 minutes, or until warm and crispy.