Preheat donut maker or if using traditional donut tins- preheat oven to 350.
Add flour, sugar & baking powder to a large bowl. Mix & then create a well in the center.
Pour in the milk and mix until almost all combined. Then add the eggs, mixing well.
Add the melted and cooled butter- mix until well combined.
Fold in the cinnamon.
Spray the donut maker wells or donut pans with cooking spray.
Add a portion of batter to a pastry bag & pipe the batter into the donut maker wells or into the donut pans.
Cook in the maker for 6 minutes or 10-12 in the oven.
Remove & immediately put the hot donuts in the prepared paper sack. Crimp down tightly to hold in heat & shake around to coat the donuts with the sugar mix. You can leave them in the closed bag while refilling the donut maker for the next batch.
Remove the coated donuts & let them cool on a wire rack.
Store in airtight container. I keep mine refrigerated & then warm for about 20-30 seconds in the microwave before serving.