Preheat your oven to 160°C for a fan oven or 170°C for a conventional oven.

Wash the peaches and raspberries thoroughly. Slice the peaches into wedges and toss with raspberries and caster sugar in a bowl.

In a large bowl, whisk together the plain flour, baking powder, and caster sugar. Cut in the cold butter until crumbly, then add milk.

Spoon dollops of the topping over the fruit mixture in the baking dish, leaving a few gaps for bubbling.

Bake for 25-30 minutes until golden brown and the fruit bubbles.

Let the cobbler cool for 10 minutes before serving warm.