Preheat oven to 400 ℉. Combine flour, oats, sugar, baking powder and soda in mixing bowl. In a 1 cup measuring cup beat egg, then measure in oil, add vanilla and buttermilk, blend thoroughly. Add liquid mixture and pumpkin to dry ingredients, mixing just enough to combine, adding milk to proper consistency. Do not over mix, as you want small lumps. Fold in pecans and chocolate chips if desired. Spray muffin pan with non-stick spray. Spoon mixture into muffin pan, sprinkle coarse sugar on tops. Bake for 20-22 minutes.