Line 12 standard (1/3 cup) muffin cups with cupcake liners.
In a large bowl, mix together the flour, oats, baking powder, baking soda, salt, cinnamon, ginger, cloves, and nutmeg.
In a medium bowl, whisk together the buttermilk, pumpkin, maple syrup, brown sugar, oil, egg, and vanilla.
Add the wet ingredients to the dry ingredients, and whisk just until the ingredients are well incorporated. Try not to overmix!
Divide batter between the 12 muffins cups.
Bake for about 22 - 25 minutes, until the top of the muffins spring back when poked and a toothpick inserted into the center of one of the muffins comes out clean. Angels may sing, too. Okay, I'm kidding about that last one.
Move muffins to a wire rack on top of a couple of paper towels (helps with clean-up) and allow to cool for 10 - 15 minutes.
Mix up the glaze - whisk together the powdered sugar, vanilla, cinnamon, syrup, and milk until smooth and shiny.
With a spoon, drizzle the glaze over the tops of the muffins.
Maple Pumpkin Oat Muffins with Cinnamon-Maple Glaze