Preheat your oven to 400F.
Prep the apples: You can peel the apples or leave the skin on (whichever you prefer). Grate the apples then measure out 1 & ½ cups (or 210g) loosely packed.
Squeeze out any excess liquid from the shredded apples - you can do this by simply grabbing it with your hands and squeezing. Set aside the shredded apples.
In a medium bowl, whisk together flour, baking powder, baking soda, cinnamon, and salt. Set aside.
In a large bowl, whisk together sugar, butter, eggs, and vanilla to combine. Then whisk in the milk followed by the grated apples.
Finally mix in the dry ingredients until streak free. Take care not to overmix!
Butter 2 (6 count) donut pans and dust with flour. Tap out any excess flour.
Fill your greased donut tin with the batter, filling each donut mold ¾ of the way full.
Bake the donuts in the center of your preheated oven for 7 to 10 minutes or until a skewer inserted into a donut comes out with a few moist crumbs.
Cool the donuts for 5 minutes in the pan then flip them onto a wire rack while they're still hot.
Set the baked donuts aside to cool enough to handle.
Pour your butter into a shallow bowl (large enough to dip a donut in), and set aside.
In a medium bowl (also large enough to fit a donut in), mix together sugar and cinnamon.
Quickly dip the donut into the butter and turn to coat both sides. Allow any excess to drip off then drop the donut into the cinnamon sugar and toss to coat all sides.
Repeat with the remaining donuts then serve!
