Preheat oven to 350 degrees F (180 degrees C). Peel and shred the Apple (1).
Combine All-Purpose Flour (1 1/2 cup), Baking Powder (1 3/4 teaspoon), Salt (1 1/2 teaspoon), Ground Nutmeg (1/2 teaspoon), and Brown Sugar (1/2 cup) in a bowl.
Use a fork to blend in Unsalted Butter (1/4 cup) until the mixture is crumbly.
In another bowl, whisk the Egg (1) and then add shredded apple and Milk (1/2 cup) to the bowl. Add this mixture to the flour mixture. It will make a thick batter.
Place the batter into a ziplock bag and cut off the corner tip of the bag. Using it like a pastry bag, fill the donut tin up about half way.
Bake in the preheated oven for about 20 minutes.
While they are still warm, dip the donuts into mixture of Ground Cinnamon (to taste) and Granulated Sugar (to taste).