Warm the milk in a saucepan and pour it into a bowl. Crumble the yeast into the milk and stir until dissolved.
Add flour, salt, and sugar and mix together.
Crack the eggs and separate the whites from the yolks. Save the whites for later. Stir the yolks into the batter.
Let the batter rise for 30 minutes.
Beat the egg whites until stiff.
Stir a quarter of the egg whites into the batter and then gently fold in the remaining whites.
Heat the pan, add 1 tablespoon of fat in each hole, and fill the holes with batter - they should be almost filled, but not completely!
Cook the æbleskiver on one side until golden but still liquid in the middle. Tip them 90o and add a bit more batter before fully flipping them over. You may need to turn and adjust the æbleskiver a bit during cooking to ensure they are evenly baked without burning.
Place them in a bowl with a paper towel at the bottom.
Serve with powdered sugar and jam.
