For the batter, mix together the flour, rolled oats, brown sugar, baking powder, cinnamon, nutmeg, and salt. Mix in the egg and buttermilk. Gradually stir in the milk. For the vegan prep with no dairy - you would just mix all the dry ingredients together - flour, oats, baking powder, brown sugar, cinnamon, nutmeg and salt.
Core the apples and slice vertically into thirds, for doughnut-size rings Each apple should give you 3 rings.
Heat the oil in a deep frying pan to 180˚C (350°F).
Evenly coat each apple slice, front, back and center hole, in the batter mix as if you were breading a chicken cutlet. If you are not using the batter and opting for the vegan preparation, pat each apple ring dry with paper towel and generously coat each ring with honey on both sides and in the hole, then dip into the dry mixture in Step # 1.
Carefully lay the doughnuts into the oil and fry for about 2-3 minutes on each side, until golden brown. Tong out and on paper towel before coating in powdered sugar and cinnamon.