In a large mixing bowl, whisk together the flour, sugar, baking powder, baking soda, salt, and pumpkin pie spice.
In another bowl, mix the pumpkin puree, milk, egg, and melted butter until well combined.
Pour the wet ingredients into the dry ingredients and stir until just combined. Do not overmix.
Lightly grease the waffle iron and pour the batter onto the preheated waffle iron. Cook according to the manufacturer's instructions until golden brown and crisp.