Put oatmeal in mixing bowl and add buttermilk. Let it sit for 2 minutes. Add egg whites and pumpkin and mix together. Add 1 tsp vanilla extact and the brown sugar. Sift remaining ingredients except for the turbinado sugar and mix with the wet ingredients. Divide mixture into 4 muffin cups that have been sprayed with pan spray. Sprinkle turbinado sugar on tops of muffins. Bake in preheated 400 degree oven for 20 minutes. Let cool for five minutes then remove from pan and enjoy.