Preheat the oven to 350 degrees F. Spray loaf pan inside with non stick spray or line with parchment paper.
Place buttermilk and oats in a small mixing bowl and let rest for 15 minutes Meanwhile, whisk the pumpkin, maple syrup, oil, brown sugar, vanilla, and eggs in a medium mixing bowl.
In another medium bowl, whisk the flour, pumpkin pie spice, baking powder, baking soda, and salt. Then mix the oats and buttermilk into the pumpkin mixture
Slowly add the flour mixture to the pumpkin mixture until just combined. Pour into the prepared loaf pan. If you choose to sprinkle some more oats, shelled pumpkin seeds or dried cranberries on the top do so now.
Bake for about 55-70 minutes, or until a toothpick comes out mostly clean with moist crumbs attached. (start with 55 minutes, if wet looking in center check every 5 minutes after that with toothpick until all that is attached is moist crumbs). ** 18-22 minutes for muffins
Cool on a wire rack for 10 minutes before removing from the loaf pan.