Preheat the oven to 350°F and spray your mini donut pans with pan release. Make sure to get every nook and cranny.
In a bowl, whisk together the sugar, flours, dried buttermilk, ginger, baking powder, baking soda, and salt. Set aside.
In a large bowl, whisk together the water, melted butter, and egg. Add the dry ingredients to the wet ingredients. Whisk or stir until just combined.
Fill each cavity in the donut pan with 2 tablespoons of batter (no more than halfway). Bake 8- 10 minutes. The donuts should spring back when poked.
Cool in the pans for 2 minutes, then flip them out onto a cooling rack. Cool completely before adding the glaze.
Cool the pan completely, lightly coat with baking spray and fill with another round of batter. Repeat until all of the batter has been used.
Mango Glaze
Whisk together the powdered sugar, corn syrup, mango flavor, orange color, and 2 tablespoons of water. If too thick, add water a tiny bit at a time. If too thin, add a bit more powdered sugar. Taste and adjust flavor as needed.
Use a piping bag or a spoon to add the glaze to the mini ginger donuts, or dunk the tops of the donuts into the glaze.
Notes
Glaze the donuts the day they will be served. After several hours, the glaze will begin to soak into the donuts. They are still delicious, but they won't look as pretty.