3 large ripe bananas, peeled, sliced
450g/1lb jar dulce de leche (sweet toffee sauce), available from Spanish delicatessens and some supermarkets
1 tbsp icing sugar
100驳/3陆辞锄 dark chocolate, grated, to serve
300g/10陆oz oat or ginger biscuits
60驳/2录辞锄 butter
350ml/12录fl oz double cream