In a small bowl, combine 1 Tbsp. sugar and 1 tsp. cinnamon. Set aside.
Preheat oven to 400 degrees. Grease 14 muffin cups with cooking spray.
In a small bowl, combine whole wheat flour, all-purpose flour, salt, 1/2 tsp. cinnamon, nutmeg, and baking powder.
In a large bowl, mix eggs, sugar, orange extract or zest, oil, and milk. Add the sweet potatoes and mix until thoroughly combined.
Add dry ingredients to wet ingredients and mix. Spoon batter into prepared muffin cups. Sprinkle tops with cinnamon-sugar mixture.
Bake 20-25 minutes or until the tops spring back when touched. Store in an airtight container.