Original Recipe for Danish Aebleskiver (Pancake balls)

Separate the egg whites and yolks in separate bowls.Whisk the sugar and egg whites fluffy and stiff. The bowl must be completely clean and dry. A tiny bit of water will make the eggs whites impossible to whisk stiff. Set aside. Mix the egg yolks, all-purpose flour, natron (baking soda), salt and vanilla sugar together in a separate bowl.Use a hand mixer to mix the ingredients while gradually adding the buttermilk. Keep mixing until the batter is uniform.Melt the butter and let it cool off a bit. Slowly add the cooled butter to the buttermilk mixture while whisking.Use a wooden spoon or similar to slowly mix the stiff eggs whites in the batter.You need a special Aebleskive pan for frying. You can get one online or maybe at your local kitchen store.Heat up the Aebleskive pan at medium heat and add a small piece of butter in each hole. Fill the holes 3/4 with the Aebleskive batter.When the batter starts to get firm and you can turn them over without cracking, then turn the Aebleskiver 90 degrees (using a wooden stick or similar) and let the batter flow into the pan.At this point there is a hole in the side of the Aebleskive. Pour a little extra batter into the hole and turn the Aebleskive another 90 degrees so that the hole gets closed.When the Aebleskiver have a solid surface turn them regularly so they get an even and light-brown crust.