Combine the flour, sugar, cinnamon, nutmeg, baking powder, baking soda, and salt in a large mixing bowl.
In a small bowl, mix together the buttermilk, vanilla, egg, and oil until well combined.
Pour the wet ingredients into the dry and whisk together until most of the lumps are gone. Do not overmix.
Heat a large skillet over medium heat and spray with cooking spray.
Pour 1/4 cup of batter into the skillet and cook until bubbles form on the surface. Flip the pancake and cook until browned on the bottom and the center is done.
While cooking the pancakes, place marshmallows on a foil lined sheet and place under the broiler for 2-3 minutes or until golden brown on top. Remove from the oven and use a spatula to carefully transfer the marshmallows to the pancake tops.
Drizzle syrup over the pancakes and crumble on the graham cracker.