Mix together the milk and pumpkin until smooth. Add the starter and brown sugar and mix to combine. Lastly, add the flour and mix again until you have a thick and smooth batter. Cover and let stand at room temperature overnight, or about 8-12 hours.

After fermentation, the batter should have risen some and have a few bubbles on the surface.

In a medium bowl, mix the eggs then add the oil or butter and continue mixing until they are smooth. Pour into the bowl with the overnight sponge.

Add the cinnamon, pumpkin pie spice, salt, baking soda, and vanilla. Mix to combine. Mixture should be thick but pourable, add a bit more milk if it’s too thick.

Heat the waffle iron and use additional oil or butter to brush the grates on both sides. Do this before each waffle.

Scoop the batter onto the waffle iron, smoothing out slightly. It should cover about ¾ of the surface of the waffle iron.

Cook until golden brown and cooked through.

Serve the waffles right away with your favorite toppings: whipped topping, melted butter, maple syrup, honey, etc.