In a large bowl, whisk together the flour, brown sugar, baking powder, baking soda, salt, pumpkin pie spice, and cinnamon.
In a separate bowl, whisk together the milk, pumpkin puree, egg, melted butter, and vanilla extract until smooth.
Pour the wet ingredients into the dry ingredients. Gently stir just until combined. Do not overmix; a few small lumps are fine.
Let the batter rest for about 5 minutes while heating the skillet.
Heat a lightly buttered or oiled skillet or griddle over medium-low heat.
Pour about ¼ cup of batter onto the skillet for each pancake.
Cook for 2–3 minutes, or until small bubbles appear on the surface and the edges look set.
Flip and cook for another 1–2 minutes, until golden brown and cooked through.
Serve warm with butter, maple syrup, whipped cream, nuts, or your favorite toppings.