F ool is one of my go-to desserts for two reasons: first, its pure simplicity – it’s little more than custard or yoghurt mixed with whipped cream and pureed fruit – and, second, its adaptability to the seasons. Gooseberry, rhubarb and strawberry are traditionally the most foolish fruits, but just about any fruit goes. British blackberries are still available and apples are in their prime right now, so I’ve gone for those, but use whatever you’ve got in store.

I usually make fool with yoghurt, not least because it’s much less work than making custard from scratch, but I’ve got lots of leftover custard from this week’s Food Filter taste test , so I’m going for a custard base here.…