Peel the pineapple, cut into wedges, remove the stalk. Peel the mango, cut the pulp from the stone, cut everything into small pieces! Weigh (should add up to 1 kg), stir the preserving sugar into the pulp. Cover and chill for approx. 24 hours.
Only then bring to the boil, stirring constantly. Make sure to let the mixture boil for about 3 minutes. Stir in the rum.
Pour the mixture into prepared jam jars. Close immediately.