Preheat the oven to 350ºF (180ºC). Grease and flour a 24-serving mini muffin pan.* Do not use muffin liners. (The muffins need to form an outer crust. This prevents them from absorbing too much melted butter in the last step.)
In a medium-size bowl, whisk together the flour, baking powder, salt, cinnamon, ginger and nutmeg.
In a large bowl, whisk the granulated sugar, brown sugar, oil, egg and vanilla extract together until smooth and well combined. Stir in the puréed apples. Stir in the flour mixture just until combined. The batter will be thick.
Transfer the batter to prepared pan, filling the muffin cups about 2/3 full. Bake until a toothpick inserted into the center of the muffins comes out clean, about 9-11 minutes. Do not over bake! Be diligent, since over baking can happen very quickly with mini muffins. Let the muffins cool in the pan for 5 minutes. Turn the muffins out and place on a cooling rack.
Cinnamon Sugar
Whisk the cinnamon and granulated sugar together in a shallow bowl until well combined. Briefly dunk the warm muffins in the melted butter, then roll them in the cinnamon sugar.