Whip flour, egg yolks, melted butter and whipping cream until creamy. Add cardamom, vanilla, lemon zest, salt, sugar and calvados, and stir dough well. Whip egg whites until stiff and gently fold into batter. Bake Æbleskiver on the spot and sprinkle with sugar.
Serve Æbleskiver with sugar and jam.
Bake Æbleskiver in a special frying pan with spherical indentations. Brush the frying pan with butter before baking.