Preheat the oven to 180 ° C (convection 160 ° C, gas level 2 - 3). Separate the eggs, beat the egg whites until stiff. Mix the egg yolks, 1 tablespoon of water, margarine and sugar until frothy. Mix in the rum, flour, baking powder and desiccated coconut and fold in the egg whites.
Grease a springform pan (diameter 26 cm) and sprinkle with flour. Pour in the dough, smooth it out and bake for 30 to 35 minutes.
Heat the apricot jam with 2 tablespoons of water. Brush the cake with it and sprinkle with desiccated coconut.
This fluffy coconut cake tastes great with coffee or hot chocolate.