Bursting with peaches and blueberries, this summery tray bake would be a tasty addition to a picnic basket.
For the crumble topping, place all of the crumble ingredients into a large bowl. Rub the butter into the flour until the mixture resembles breadcrumbs. Set aside.
For the cake preheat the oven to 180C/350F/Gas 4. Grease a 23cmx30cm/9inx12in baking dish with a little of the butter
Sift the flour into a bowl and stir in the sugars. Rub the butter into the flour mixture until it resembles breadcrumbs. Stir in the baking powder, salt, egg yolks and milk and stir until well combined.
Whisk the egg whites in a bowl until soft peaks form when the whisk is removed. Fold the egg whites into the cake mixture.
Spoon the cake batter into the baking dish and scatter over the blueberries and peach slices.
Sprinkle over half of the crumble topping and bake for 40-50 minutes, or until golden-brown on top and a skewer inserted into the middle comes out clean. Remove the cake from the oven and set aside to cool for 10 minutes.
Meanwhile for the jam, heat the peaches and the juice from the can, blueberries, sugar, flour and juice in a saucepan over a medium heat until boiling. Reduce the heat and simmer for 8-10 minutes, or until the mixture is thick and jammy. Remove the pan from the heat.
Spread the jam over the cake and sprinkle over the remaining crumble topping.
Return the cake to the oven and bake for a further 8-10 minutes, or until the topping is crisp and golden-brown.
