Preheat oven to 350°F and grease a standard muffin tin or line with silicone liners.
Place the rolled oats in a high-speed blender and pulse until they reach a fine, flour-like consistency.
In a large mixing bowl, mash the banana until smooth, then whisk in the pumpkin puree, liquid egg whites, maple syrup, and vanilla extract.
Fold the oat flour, baking powder, cinnamon, ginger, nutmeg, cloves, and sea salt into the wet ingredients until just combined.
Distribute the batter evenly among 12 muffin cups, filling each about three-quarters full.
Bake for 22-25 minutes, or until a toothpick inserted into the center comes out clean and the tops are springy.
Allow the muffins to cool in the pan for 5 minutes before transferring to a wire rack to cool completely.