Make the crumble topping; in a medium mixing bowl, combine all the ingredients from flour to oil, and stir well with a fork to combine, making sure all of the dry ingredients are moistened by the oil.
If making in advance, transfer to an airtight container and keep in the fridge.
On the day of serving, preheat the oven to 180 degrees Celsius.
Chop the fruit in small chunks.
Arrange the fruit chunks over the bottom of a baking dish and mix in the tapioca starch and 1 Tbsp coconut sugar. Sprinkle evenly with the topping.
Insert in the oven and bake for about 40 minutes, until the fruit is tender and the topping golden brown, checking regularly to make sure it doesn’t darken too much (if it does, cover loosely with a piece of parchment paper).
Serve slightly warm or at room temperature.