01 - Preheat oven to 350°F (180°C).
02 - In a large bowl, combine berries, granulated sugar, cornstarch, and vanilla extract. Toss gently until evenly coated.
03 - Pour berry mixture into a greased 8-inch square baking dish or similar ovenproof dish.
04 - In a separate bowl, whisk together oats, flour, shredded coconut, brown sugar, cinnamon, and salt.
05 - Add cold cubed butter to dry ingredients. Rub together with fingertips until mixture resembles coarse crumbs. Stir in vanilla extract.
06 - Sprinkle crumble mixture evenly over the berry filling.
07 - Bake for 35 minutes until topping is golden brown and berry filling is bubbling around edges.
08 - Let stand for 10 minutes before serving. Serve warm with vanilla ice cream or Greek yogurt if desired.