1. Heat oven to 350 degrees.

2. Spray pan (or doughnut maker) with nonstick spray. Set aside.

3. In a bowl, combine sugar, flour, cinnamon, and butter until resembling a coarse meal. Chill in the freezer while preparing the batter.

4. In a bowl, whisk together dry ingredients.

5. In a separate bowl, whisk together wet ingredients, then gently fold the wet mixture into the dry mixture.

6. Spoon or pipe the batter into the prepared doughnut pan (or maker).

7. Divide the crumb topping evenly among the doughnut tops.

8. Bake for 10-11 minutes in the oven. If cooking in a doughnut maker, follow the instruction manual.

9. Allow doughnuts to cool for a few minutes before transferring to a wire rack.

10. In a small bowl, whisk together the powdered sugar, milk, and vanilla.

11. Drizzle the mixture over the doughnuts and serve.