Aebleskiver (Danish Pancake Puffs)

Separate the egg whites and yolks. In a completely clean and dry bowl, whisk the sugar and egg whites until fluffy and stiff, and set aside. In a separate bowl, mix the egg yolks, all-purpose flour, baking soda, salt, vanilla sugar and cardamom. With a hand mixer, continue blending the ingredients while gradually adding the buttermilk. Melt the butter, leave to cool a bit, then whisk into the buttermilk mixture. Finally, use a wooden spoon to slowly fold the stiff egg whites into the batter.
To cook the aebleskiver, you’ll need a special cast iron pan with round indentations. Heat the pan to medium heat, then add a small piece of butter in each hole. Fill each hole up to ¾ with the batter. As they start to become firm, gradually turn each aebleskive sideways to shape it into a puff/ball. You can try to fill them with chocolate chips, jam, or small pieces of apple. Keep turning the aebleskiver until they get an even and light-brown crust. Keep them warm and serve with jam and icing sugar.