In a medium bowl beat the eggs and sugar with an electric mixer until very thick, about 5 minutes. Stir together the flour and cardamom add it to the egg mixture alternately with the heavy cream.
Heat the krumkake iron over the stovetop on medium high heat. When it is hot enough a drop of water will dance around on the surface. Drop batter by tablespoons onto the centre of the iron. Close the cover and cook over medium heat for about 30 seconds on each side. Carefully peel the biscuit from the iron and roll in a tight roll or cornucopia shape using metal forms or wooden dowels. Remove from forms and continue with more batter.