Place the peach pieces in a saucepan with a little water and the brown sugar. Cook until the peaches have softened slightly.
Place the apples and their juices in a lightly greased oven proof dish.
Combine the flour and sugar in a large bowl and then rub the butter through with your fingertips until it resembles breadcrumbs (you can do this in a food processor if you want). Add a couple of tablespoons of water as required to form a dough.
Using a tablespoon drop 6 large dollops of the dough on top of the cobbler. Bake in the oven for 30 – 40 minutes, or until the apples are tender and the crust is golden brown.