Melt butter first and set aside so it has time to cool.
In a large bowl, whisk together flour, brown sugar, baking powder, baking soda, salt, cinnamon, ginger, nutmeg, and allspice until well-combined and any clumps from the brown sugar are broken up.
In a separate bowl, whisk together milk, pumpkin puree, eggs, and vanilla extract until thoroughly combined.
Drizzle the melted, slightly cooled butter into the milk mixture, whisking to combine.
Pour the milk mixture into the dry ingredients and use a spatula to gently fold the ingredients together until just combined (don’t over-mix or pancakes will be dense and rubbery).
Set batter aside and lightly spray a skillet with cooking spray or lightly brush the pan with a bit of canola or vegetable oil (or you may use about half a tablespoon of butter). Turn stovetop heat to medium and allow the skillet to heat for several minutes or until you can feel the heat radiating from the pan when you hover your hand several inches above the surface.
Scoop pancake batter (I do about ½ -⅔ cup but you can make the pancakes any size you’d like!) into the center of the skillet and, if it’s forming a mound in the center, use a spoon to gently spread the batter so you have an even layer (this helps the pancake to cook evenly, otherwise you’ll have a thick center that will be slightly underbaked).
Cook until the edges begin to appear cooked through and bubbles that form in the batter begin to burst. Carefully flip the pancake and continue to cook until the other side is golden brown and pancake is cooked through (you can use a knife to check that the center of the pancake is dry).
Remove to a plate and repeat until all batter is used — Re-spray or brush the pan with oil between each pancake.
Serve pancakes fresh and warm, topped with butter, whipped cream, and maple syrup!