Pre-heat the oven to 200 °C. Combine the berries, granulated sugar and vanilla extract and place in a pie dish. For the topping, mix the rich dark brown sugar, flour, cinnamon and oats. Add the butter and mix into a crumbly mixture. Spread evenly over the berries and bake in the oven for 15 to 20 minutes or until it is golden brown. Serve hot with home-made vanilla cream (see recipe for tartlets).