Preheat the waffle maker according to the manufacturer’s instructions. Lightly grease it with butter, oil, or nonstick cooking spray if needed.
In a large bowl, whisk together the flour, cornstarch, brown sugar, baking powder, baking soda, salt, cinnamon, ginger, nutmeg, and cloves.
In a medium bowl, whisk together the pumpkin purée, milk, eggs, melted butter, and vanilla extract until smooth.
Pour the wet ingredients into the dry ingredients. Stir gently until just combined. Do not overmix; a few small lumps are fine.
Pour the recommended amount of batter into the center of the hot waffle maker. Close the lid and cook until the waffle is golden brown, crisp, and cooked through, usually 3 to 5 minutes depending on your waffle maker.
Transfer the cooked waffle to a wire rack. Do not stack hot waffles, as trapped steam can soften them.
Repeat with the remaining batter, greasing the waffle iron as needed.
Serve warm with maple syrup, butter, whipped cream, toasted pecans, or your preferred toppings.