Sweet Potato Muffins

For the muffins:
2 cups old fashioned rolled oats
1 cup all purpose flour
1 cup whole wheat flour
1/2 tsp salt
2 tsp baking powder
1 tsp baking soda
1 tsp ground cinnamon
1 tsp ground pumpkin pie spice
2 cups cooked and mashed sweet potato
1/2 cup brown sugar 1/2 cup raw sugar
2/3 cup applesauce (no sugar added)
2 tsp olive oil
1/2 cup nonfat yogurt
1/4 cup milk
2 large eggs
2 tsp pure vanilla extract

For the Streusel:
1/3 cup all purpose flour
1/3 cup oatmeal
1/3 cup brown sugar
1/4 tsp sea salt
1 tsp pumpkin pie spice
1/2 tsp cinnamon
4 tsp unsalted butter
1/3 cup walnuts, very finely chopped

Preheat oven to 400 degrees.

To make the streusel topping, combine the first seven ingredients, cutting in butter with either your fingers or a pastry cutter. Once you have a lot of small crumbs, add in the walnuts. Set aside.
In a medium bowl combine oatmeal, flours, salt, baking powder and soda, cinnamon, and pumpkin pie spice. In a separate small bowl, mix together sweet potato, sugars, applesauce, yogurt, milk, egg, and vanilla. Pour liquid mixture into a well in the dry ingredients and stir until just moistened, being careful not to over-mix. Scoop into muffin tins, covering each muffin with small amount of streusel, and bake for 16-18 minutes.

(This recipe was derived from here)