Method

1. First freeze the bananas for the ice cream: peel the bananas for the ice cream, cut into chunks and freeze.

2. Preheat the barbecue or grill.

3. For the grilled bananas: insert a sharp knife in one end of each unpeeled banana and insert a rosemary sprig. Place the bananas onto the barbecue and cook for 3-4 minutes on each side, or until the skin is dark brown and starting to split.

4. To make the toffee sauce: melt the butter, sugar, treacle, golden syrup and cream in a pan over a medium heat and bring to the boil.

5. To make the ice cream: Place the frozen banana chunks into a food processor and blend until smooth. Add the vanilla, sweetener and half the buttermilk and process for a few seconds. With the motor still running pour in the remaining buttermilk in a thin steady stream. Let the machine run until the mixture is smooth and creamy.

6. To serve: remove the rosemary from the bananas and cut them open, leaving the skin on. Put a good spoonful of toffee sauce and a scoop of the ice cream on top. Serve straight away.