Preheat oven to 350. Grease donut pan with oil or cooking spray.
Whisk together the flour, baking powder, nutmeg, cinnamon, & sugar together in a mixing bowl & set aside.
Whisk the milk, yogurt, egg, melted butter, & vanilla in a separate bowl. Add the dry ingredients (flour mixture) to the bowl & mix until just combined (being careful not to over mix). Add the sprinkles & gently fold them into the batter.
Fill donut pan with batter, about ¾ of the way full. (I use a small spoon to scoop the batter into the pan & then the back side of the spoon to smooth the batter down & even it out).
Bake 10-12 minutes or until the edges are just starting to brown. Let cool in pan for 5-10min. then move to wire rack to finish cooling (a rubber spatula works well to remove to the donuts if they aren't coming out easily).
For the Frosting:
Combine all ingredients & mix until you have a thick creamy frosting. You may have to add a little extra powdered sugar or cream to get a thick consistency. Spread frosting on the top of cooled donuts & decorate with sprinkles if desired.
Recipe by THE SEMISWEET SISTERS at https://www.thesemisweetsisters.com/2014/10/19/baked-funfetti-cake-donuts-recipe/