- Blend the bananas with the lemon juice and 50ml (2fl oz) of the cream until smooth, but don't over-mix
- In a large bowl, whisk the egg yolks with the vanilla extract and the caster sugar until pale and thick. In a second bowl, whip the remaining cream until soft peaks form. Then in a third bowl, whisk the egg whites until very stiff
- Fold the whipped cream into the egg yolks, then the banana mixture into it also. Gently mix in the egg whites until combined
- Add a third of the cream mixture to the prepared tin, drizzle over a third of the dulce de leche then repeat, using up all of the mixture. Cover and freeze overnight before serving.