In a large bowl, whisk the sugar, baking powder, salt, cinnamon, ginger, and nutmeg together. Add the egg and yolk, melted butter, milk, and molasses until just combined. The batter will be thick.
Preheat your waffle iron. Place a tablespoon of batter in each waffle cavity and cook for about 3 minutes, or until golden brown. Remove to a wire rack and repeat for the remaining batter.
To glaze:
In a small bowl whisk together all the glaze ingredients until smooth. Drizzle or dunk the slightly cool doughnut into the glaze. Let sit until set. Doughnut waffles are best served the day they are made.