Heat oven to 190°C (375°F). Sift flour and cinnamon into a bowl. Cut butter into tiny cubes and rub lightly into the flour with your fingertips, leaving it clumpy. Mix lightly with sugar and ground almonds.
Peel and roughly chop all fruit as appropriate, and arrange in a jumbled layer in a large buttered pie dish or baking tray. Sprinkle with caster sugar. Top with crumble topping. Bake