Place the egg yolks in a bowl and whisk until light and fluffy. Combine the sugar and water in a small, heavy-bottomed saucepan and stir over medium heat until the sugar is completely dissolved.
Remove the spoon and boil the syrup until it reaches the ‘thread’ stage.
It will look thick and syrupy and, when a metal spoon is dipped in, the last drops of syrup will form thin threads.
Pour this boiling syrup in a steady stream on to the whisked egg yolks, whisking all the time.
Add the vanilla essence and continue to whisk until it becomes a thick, creamy, white mousse. Gently fold in the softly whipped cream, which you have stored in a separate bowl. Pour all of the mixture into a bowl.
Swirl some of the marula ripple (below) into the ice cream, cover and freeze.