1. Blanch, peel and slice the tamarillos.
2. Drain the Wattie's Boysenberries in Syrup and reserve the juice.
3. Arrange the tamarillos and the boysenberries in a 6 cup capacity pie dish. Pour over about 2/3rds of the juice. Heat the fruit either in a microwave (3-5 minutes) or oven (15-20 minutes) until hot. The fruit must be hot before the crumble goes on.
4. Sift the flour and brown sugar into a bowl. Stir through the Weight Watchers' Berry Flakes. Rub in the softened butter. Do not worry if you are squashing the berry flakes, that's supposed to happen.
5. Sprinkle the crumble over the fruit. Bake at 190°C for 20-25 minutes until hot and golden.
Serve with yoghurt flavoured with a little of the remaining boysenberry juice.
Note: For individual serves divide the mixture between 6 individual ramekins and bake for only 15 minutes.
Variation: Use 1 x 770g can of Wattie's Simply Apple Slices in place of the tamarillos for a change.