Preheat the oven to 350℉/176℃ and grease your mini muffin tray if needed. (Enough to make 20 donut holes.)
In a medium bowl, whisk together the dry ingredients. Then add the applesauce and plant-based milk to the same bowl. Mix until combined.
Use a small cookie scoop to divide the mixture among 20 muffin tins. Do not fill to the top, remember we're making donut holes, not muffins, so you don't want them to overflow.
Bake for 7-8 minutes until a toothpick inserted into the center comes out mostly clean. Do not overbake them, or they will be dry. (They bake quickly because they're small.) Remove from the oven and let cool for 5-10 minutes before transferring them to a wire rack.
For the glaze
Meanwhile, add the milk to a small bowl, and then combine the sugar and cinnamon in a wide and shallow dish.
When the donuts are cool enough to handle, swirl them one at a time into the milk, shake off the excess, and then swirl them around into the cinnamon sugar mixture until coated on all sides. Repeat with the remaining donuts and enjoy!
Notes
Weigh your flour for the most accurate results. If you do not have a kitchen scale, spoon the flour into your measuring cup and scrape off the excess with the back of a knife. Never pack flour into your measuring cups or scoop from the bag.
Use active baking powder. Once open and sitting in the pantry for 6+ months, baking powder may start to use its effectiveness.
Wait for the donuts to cool before glazing them in the cinnamon sugar. If the donuts are too warm, the glaze will melt.
Do not stack the donuts when freshly glazed to prevent the glaze from melting. Arranging them in a single layer is best.
Leftovers keep at room temperate OR in the fridge for 2-3 days. (Refrigerate if you're in a warmer climate.) Or freeze a batch (preferably without the glaze) for up to 3 months and glaze them before serving.