Preheat oven to 350°. Spray two standard donut pan with non stick spray and set aside.
In a mixing bowl, whisk together the egg and oil. Mix in the milk and vanilla extract. Add in the flour, sugar, baking powder and salt. With the electric mixer, mix everything until just combined.
Spoon the batter into the donut pans until they are about ¾ full.
Bake for 10-12 minutes or until a toothpick or knife come out clean. Please note that these donuts will not turn a golden brown color so don't wait for that to happen. Allow to cool for 10 minutes after they are done.
Maple apple glaze
In a large saucepan over low heat, melt the butter and maple syrup. Chop the apples into small chunks and set aside.
Once the butter has melted, remove from the heat and whisk in the confectioner's sugar and maple extract. Cool for 2-3 minutes and then dip each donut into the glaze. Dip pretty quickly as the icing likes to harden fast (you can return icing to heat if needed). Add chopped apples to the tops of each donut and add extra icing if desired.