Drain the pineapple rings and collect the juice. Cut the pineapple into small pieces. Wash 250 g apples, quarter them and remove the core. Dice the apples and sprinkle with 1 tablespoon of lemon juice.
Whisk egg yolk and sugar in a hot water bath until thick and frothy. Add 2 tablespoons pineapple juice. Remove bowl from water bath and stir the mixture until cold. Add the pineapple and apple pieces. Whip cream until stiff and fold in.
Pour the mixture into 4 small moulds (each with a capacity of approx. 250 ml) and freeze overnight (but at least 4 hours). For the steamed apple slices, wash the remaining apples, quarter them, core them and cut them into narrow slices.
Bring 1/8 litre water with remaining lemon juice and vanillin sugar to the boil and stew the apple slices in it for about 5 minutes at low heat. Then drain well and let cool off. Let the parfaits thaw a little.
Arrange apple slices with the parfaits. Sprinkle with grated coconut and cinnamon and serve garnished with lemon balm leaves.