Easy, economical, bettys were popular during WW1. Try this rhubarb version. Dry the bread in a low oven for maximum crispness.
Cut 400g prepared rhubarb into 1½ cm pieces. Bake in a standard 9ins (23cms) pie dish at 180C (fan oven) or equivalent with 50g golden granulated sugar and 1 tablespoon water for 15 minutes until tender.
Whizz 100g dry bread into crumbs in a processor. Add 50g golden granulated sugar, ¼ teaspoon cinnamon and 40g melted butter. Whizz to combine. Pile onto rhubarb (spoon off excess juice). Return to oven for 10 minutes until crisp and golden. Serve with cream, custard or yoghurt.