Peel the apples, cut them into 1 cm thick slices and prick out the cores. Drizzle apple slices with lemon juice, mix flour, baking powder, egg and milk. Heat the fat in a deep fryer or a large pot to 180 °C.
Pull apple rings through the dough with a fork and bake 3-4 at a time in hot fat until golden brown. Mix sugar and cinnamon. Heat 1 tablespoon of fat, add some cinnamon-sugar and turn the apple slices in it.
Heat and light the calvados and pour over the fritters while still burning.