In a small bowl, whisk together granulated sugar and cornstarch to break up any clumps.
Place fruit in a large bowl and toss with sugar and cornstarch mixture. Add lemon juice and toss to coat. Let macerate while you prepare the topping.
In a large bowl, whisk together oats, flour, brown sugar, cinnamon, salt, walnuts, and coconut. In a smaller bowl, whisk together Monini Umbria PDO EVOO and maple syrup until combined. Add the Monini Umbria PDO EVOO and maple syrup to the dry ingredients and use a rubber spatula to stir well, until everything is moistened.
Pour fruit into a deep 9” round baking dish. Place crumble topping in an even layer on top of the fruit and bake for 40-45 minutes, until fruit is bubbly and topping is deeply golden brown. Let cool for 15-20 minutes.
Serve warm with vanilla ice cream and a drizzle of Monini Umbria PDO EVOO.