Turn the oven on to 325℉.
Make the coating by mixing the sugar and cinnamon. This will probably make a bit much, but it's great on toast. Mix it into a smallish bowl and set aside.
Spray mini muffin tins with cooking spray. Big fan of the stuff with flour in it.
In a medium sized bowl or the bowl of a stand mixer, cream together the butter (57g), vegetable oil (50g), the white sugar (100g), and the brown sugar (71g) until smooth.
Add the eggs (2) and beat to combine.
Add the baking powder (1½ teaspoons), baking soda (¼ teaspoon), salt (¾ teaspoon), nutmeg (1 teaspoon) and vanilla (1 teaspoon). Stir to combine.
Take the flour (320g) and add about ¼ of it to the mixture. Close counts. Take the milk (227g total) and add about ⅓ to the mix and stir to combine. Keep alternating until you've added all the flour and milk and combined all together.
Spoon into the prepared mini muffin pan -- I like to spoon each 'cup' about ⅔-¾ full as these will puff up when baked. If you want smaller 'doughnut holes,' adjust your baking time down accordingly.
Bake at 325℉ for 15-18 minutes, rotating the pan halfway through. They should be light golden brown and a toothpick inserted into the center should come out clean.
Remove from the muffin tin as soon as they're done. Should pop right out.
BUT while they're still warm, toss 3-4 of them at a time in the cinnamon-sugar and return to the cooling rack.
Repeat the process until all the batter is gone.
Serve warm or at room temperature. Should keep for a couple of days.