Mix Oatmeal and buttermilk together in bowl and let set for 10 minutes.Back to the oatmeal buttermilk mixture, add in one egg, vegetable oil, and brown sugar, blend well. In large bowl whisk together, flour, baking powder, baking soda, and salt. Combine flour mixture, pumpkin, and oatmeal mixture with a spatula.
Streusel Topping: Combine flour, brown sugar, oatmeal, cinnamon, and cut stick of butter into dry ingredients until you get a consistent crumble topping. A pastry cutter or a fork work good for this, or if you like you can use your food processor for a real speedy job!
Spoon muffin batter into paper lined muffin tins, cover top of batter with streusel topping, be generous.Bake at 350 degrees for 18 minutes or 22 minutes for large muffins or 15 minutes for regular sized muffin tins
Notes
These muffins freeze well. Place in sandwich bags and freeze, take out and pop in your lunch bag!Banana Nut Version: In the batter replace the pumpkin puree' with 2 ripe smashed bananas. Then add 1/4 cup chopped pecans or walnuts to the streusel topping.