Put all the ingredients for the dough – EXCEPT THE EGG WHITES – in a blender, and blend until the dough has an even consistency. Refrigerate the dough for 30 minutes.
Then beat the egg whites until forming stiff peaks and fold them carefully into the dough without beating too much air out of them.
Heat an aebleskive pan on the stove. It should be on medium heat, and be well warmed up before you start baking.
First, melt a little butter in each hole and then fill the holes with dough. Once you have dough in all the holes, turn the apple slices over. Turn them first a quarter turn, and when you have reached all the way around, turn them the last quarter turn so that they close and become completely round. If you have not filled enough dough in, you can refill them a little before turning the last quarter turn, but it should not be necessary. This is also where you can get a few apple cubes inside the aebleskiver if you like.
Then bake the apple slices while turning regularly. It takes about 5 minutes on medium heat to bake them through.
Take the aebleskiver off the pan and place them in a dish. Cover them with tin foil and keep them warm in the oven at 50 degrees celcius while you bake the rest.
Once all the aebleskivers are baked, sprinkle them with icing sugar and serve with your favorite jam.
Merry Christmas!