1. Beat the eggs and sugar together for 5 to 10 minutes in an electric mixer or by hand with a wire whisk until it falls back into the bowl in a lazy ribbon when the beater is lifted out.
2. Now, with a rubber spatula, alternately fold in half the flour, cardamom (or ginger), and sour cream, and then the remaining flour. Lightly stir in the melted butter and set the batter aside for 10 minutes.
3. If you use a non electric Norwegian waffle iron, heat it, ungreased, until it is so hot that a drop of water sputters when flicked across its surface.
4. Pour about ¾ cup of the batter in the center of the hot iron, close the top and cook over direct. heat for 5 minutes on each side. Serve with lingonberry or another tart jam.
5. This batter may be used in any regular American electric waffle iron and cooked according to the instructions for that iron.
