For the poppy seed cake, separate the eggs and beat the egg whites until stiff. Beat yolks, soft butter, sugar, rum and cinnamon until foamy. Add flour, baking powder and poppy seeds to the yolk mixture.
Mix vanilla pudding with milk so that it no longer clumps and stir into the mixture. Fold in the snow and pour the batter into a greased springform pan.
Bake at 180 °C top/bottom heat for 1 hour. Remove the cake from the pan and let it cool. Cut the poppy seed cake once, spread with jam, reassemble and sugar over.