Michelle Darmody: How to make a peach traybake that feeds a dozen

Raspberries and peaches are paired together in various desserts as they provide great balance to each other.
This soft and fruity crumble-topped sponge is baked in a large flat tray so it can be cut up and divided easily. It works well with any stone fruit, which are all coming into their own this time of year, but peaches give a particularly deep and dense colour.