Preheat the oven to 375 degrees F. In a mixing bowl add all fruit filling ingredients and mix to combine. Set aside and rest for at least 5 minutes to allow the juices to release.
In another mixing bowl combine all crumble topping ingredients except the butter. Mix well.Then add in butter and use your hands to press or pinch it into the flour mixture until it is well incorporated and forms a crumbly texture.
Pour the fruit mixture into a prepared 10 inch casserole dish or cast iron skillet. Then sprinkle the crumble mixture evenly over the top.
Bake at 375 degrees F for 35-40 minutes until the fruit is bubbly and the topping is a crisp golden brown.
Remove from the oven and allow to rest for 5-10 minutes before serving.
(optional) Serve with ice cream, whipped cream or custard. Enjoy!