Heat the oven to 180°C (160°C in a fan oven), 375°F, gas 5.
Place the butter in an oven proof dish and leave in the oven to melt.
Mix together the flour, sugar, oats, baking powder and a pinch of salt. Stir in the milk and place the mixture in the buttered dish - do not mix with the butter! Spread the berries on top and bake for 40-45 min until golden brown.
Serve in bowls with a scoop of vanilla ice cream.