Combine buttermilk, pumpkin puree, oil, eggs and vanilla in a bowl.
Mix together flour, brown sugar, baking powder, baking soda and pumpkin pie spice in a large bowl.
Make a well in the center of dry ingredients and pour wet ingredients. Mix just until combined. Allow to rest about 10 minutes.
Preheat a skillet or griddle to medium heat. Grease with butter or oil. Pour 1/4 cup batter per pancake and gently spread with the back of a spatula.
Cook until lightly browned and the bubbles on top begin to pop. Flip and continue to cook until done. About 4 minutes per side.
(Nutrition information provided is an estimate and will vary based on cooking methods and brands of ingredients used.)