Make the Waffle Batter: Mix together the dry ingredients in a large bowl. Add all of the wet ingredients to a separate medium-sized bowl and whisk until well combined. Pour the wet ingredients into the dry and mix with a spatula until just combined. It’s ok if a few small clumps remain.
1 ½ cups flour, ¼ cup sugar, 2 tsp. baking powder, ½ tsp. baking soda, 1 tsp. pumpkin pie spice, 1 tsp. cinnamon, ½ tsp. salt, 2 large eggs, 1 cup milk, ¾ cup pumpkin puree, 2 Tbsp. pure maple syrup, 4 Tbsp. butter, 2 tsp. vanilla extract