Preheat the oven to 350°F (180°C). Grease the donut pan with non-stick spray or with melted butter. Set aside.
Whisk the flour, baking powder, baking soda, salt, ground cinnamon, ground nutmeg, and granulated sugar together in a medium bowl. Set aside.
In another bowl, take yogurt, milk, butter, and vanilla. Whisk well to combine.
Add the dry ingredients to the wet mixture and stir until just combined. Do not overmix.
Baking The Donuts
Fill the batter into a large piping bag; there is no need for the tip. Cut the end of the piping bag and pipe the batter into each donut cup evenly, up to ¾ way full.
Do not overfill, as these donuts will rise well.
If you don't have a piping bag, you can also use a Ziploc bag. Fill the Ziploc bag with the batter, cut the corner, and fill the donut pan.
Bake the donuts in the preheated oven for 10 minutes or until the edges are lightly brown. Do not overbake.
Remove the donuts from the oven and let them cool down in the pan for 2 minutes.
Then transfer the donuts onto a wire rack and let them cool completely.
Coating The Donuts With Powdered Sugar
Once donuts are cooled, place the powdered sugar in a bowl. Dip each donut into the powdered sugar and serve.
Serving and Storing Suggestions
Powdered Sugar Donuts are best eaten the same day. However, they can be stored in an airtight container at room temperature for two days.
It is best to serve donuts right away, as powdered sugar will disappear if they are kept for longer.
Alternatively, if you are not eating donuts immediately, coat them with powdered sugar right before serving.
Notes
Spices: You can skip adding ground nutmeg if you prefer not to use it. Also, add more spice of your choice if you want.
Piping Bag: Using a large piping bag is an easier way to fill the batter into the donut pan. However, instead of using a piping bag, you can also use a Ziplock bag. Fill it with the batter, cut a corner, and fill the donut pan.
Filling the Pan: Do not overfill the donut pan; fill it only up to ¾ way full, as donuts will rise well.
Baking: These donuts are quick to bake, taking only 10 minutes. Keep an eye on them after 8 minutes of baking and avoid overbaking the donuts.
Coating: Coat the donuts with powdered sugar just before serving, as it will disappear if kept for longer.