Beat egg yolks until light and fluffy; add the sugar and salt. Sift the flour with baking powder and baking soda; then add to the egg mixture, alternating small amounts with the addition of the buttermilk, as you continue mixing. Beat the egg whites until stiff, then gently fold them into the batter. On stovetop, preheat the aebleskiver pan on medium heat. Place approximately 1/2 teaspoon butter in each cavity and heat until butter is foamy. Pour a little batter into each cavity in pan, filling each about 2/3 full. *Note: If you wish to fill the aebleskiver with a little applesauce or sliced apple, jam, jelly, or preserves; spoon a small amount (1-2 teaspoons) into the center of each cavity at this point in cooking. Cook aebleskiver over medium heat until golden brown and crisp on bottom. Turn each aebleskiver with a fork to cook the other side. The aebleskiver is done when a toothpick, or cake tester, inserted in the center comes out clean. The total cooking time is about 2-3 minutes. Important Note: Add a little more butter to the aebleskiver pan cavities after making each batch. Remove aebleskiver from pan and dust with confectioners sugar, or roll them in granulated sugar. Serve while still warm with jam or applesauce. Tips: You can add a small amount of cinnamon, cardamom, vanilla, grated lemon or orange zest to this recipe if desired. Aebleskiver may be refrigerated and are delicious re-warmed in the microwave for 25-35 seconds. Makes approximately 2 dozen aebleskiver.