1 cup peeled, cooked, mashed sweet potatoes, cooled
1/3 cup chopped unsalted walnuts
Preheat oven to 350°F. In a blender, pulverize oats into fine flour. In a large bowl, combine oat flour, cinnamon, baking powder, nutmeg, baking soda and salt. In a small bowl, whisk egg; stir in yogurt, maple syrup, oil and vinegar. Add egg mixture to flour mixture; stir until just combined. Fold in potatoes.
Line a 9 x 5-inch glass loaf pan with parchment paper and mist with cooking spray. Pour batter into loaf pan. Sprinkle walnuts over batter and press down on nuts lightly. Bake for 1 hour, until a toothpick inserted in center comes out clean. Let cool in pan for 30 minutes; remove and cool completely on a wire rack.