Beat the egg whites using an electric mixer until they hold a stiff peak.
Combine the flour, baking powder, sugar, baking soda, salt, baking soda, egg yolks, melted butter and buttermilk in a bowl and beat until smooth.
Heat a half tablespoon of oil into each cup of the aebleskiver pan over medium-high heat until hot.
Fill each cup with batter until they are about ¾ full.
As soon as a shell forms over the top of the aebelskiver, about 30 seconds, use a thin skewer to rotate each aebleskiver. Continue to cook the aebelskivers, rotating every 30 seconds until they are golden on all sides, and the center is cooked.
Repeat with the remaining batter.
Server immediately with powdered sugar, jam or syrup.
Recipe by The Little Chef at http://littlechefblog.com/aebleskiver/