For the pineapple tarts, beat the egg whites until stiff. Preheat the oven to 180°C. Beat the sugar with the egg yolks and water until foamy. Fold in the nuts and gradually the flour. Gently fold in the beaten egg whites.
Pour the batter into small greased tartlets and bake in the oven for about 15 minutes.
Let the small tartlets cool down and spread with the jam, so that the pineapple tartlets are nice and juicy.
Top each tartlet with a pineapple slice and place a cocktail cherry in the center.
Cover with cake jelly and store the pineapple tarts in a cool place until the jelly has set.