Soak gelatine in cold water. Beat the egg yolks with sugar, vanillin sugar, lemon zest and salt for approx. 10 minutes until thick and creamy. Whip the rum into it
Squeeze out the gelatine and dissolve over a mild heat. First stir in a little rum cream, then stir into the rest of the cream. Cover and chill until it begins to gel
Whip the cream until stiff and fold into the rum cream. Divide into four dessert glasses and chill for about 2 hours. Dust with cocoa. Possibly decorate
Traditionally, Frisian rum cream is prepared with egg yolk only. If you want to use the egg whites as well: whip them until stiff and fold in only 100 g instead of 250 g of whipped cream. You can also soak 2-3 tablespoons of raisins in the rum and fold them into the cream