Prepared any desired fillings (see ideas below) and set aside. Whisk together flour, baking soda and baking powder; set aside. Carefully separate egg whites from egg yolks (careful not to get any yolk in the whites). Place whites in glass or metal oil free bowl; set whites aside.
Beat egg yolks until smooth; add sugar, salt and lemon extract. Alternating, beat in buttermilk and flour mixture.
Using clean oil free beaters, beat egg whites until light and fluffy. Fold egg whites into flour buttermilk mixture.
TRADITIONAL METHOD OF COOKING:
Heat Aebleskiver pan over medium heat; brush each pan indentation/cup with melted butter (about ⅛-¼ teaspoon). Fill each cup almost full with batter; cook until sides are bubbly and set enough to turn. Using a knitting needle, crochet hook or wooden skewer, hook edge of Aebleskiver and turn ¼ turn allowing batter to run into the cup. Continue to cook and turn until all sides are browned.
Enjoy plain or, because this method has a tendency to create a bit more of a hollow in the center, fill with jam/jelly and cream fillings. Top with powdered sugar.
STUFFED METHOD OF COOKING:
Heat Aebleskiver pan over medium heat; brush each pan indentation/cup with melted butter as directed above. Fill each cup ⅓ full (approximately level tablespoon); add ½-1 teaspoon filling; top with an additional 1-tablespoon batter. Cook until edges are bubbly and dry. Using two knitting needles or skewers, turn each Aebleskiver over and continue to cook opposite side.
Place Aebleskivers on baking sheet in 170 degree oven to keep warm while cooking remaining batter. Dust with powdered sugar, serve with chopped fruit