Preheat the oven to 350ºF. Grease a 9" pie dish and set aside.
Remove the pits from each fruit and slice them into wedges. Add all the fruit to a large bowl and mix in remaining ingredients. Transfer fruit to the prepared dish.
In a separate mixing bowl, add quinoa flakes and oats. Stir together, then add remaining ingredients. Mix with your hands until everything is combined and the mixture starts to come together in clumps.
Top fruit with crumble topping, pressing a few larger chunks in your fingers if desired.
Bake on the center rack for 35 - 45 minutes, until the juices start the bubble and fruit softens. Check crumble at the 25 minute mark and if the topping is getting too brown, gently place a piece of aluminum foil over the top to prevent burning.
Remove from the oven and serve warm with ice cream or yogurt!