Peel the peaches and add the blackberries to a bowl. Toss with the sugar, cornstarch, zest and juice. Place mixture into a large skillet or baking dish and sprinkle with salt.
In a food processor, combine the butter, sugar, ¾ cups of the oats and the flour. Pulse until evenly combined. Remove from the food processor and add the remaining oats. Toss to combine.
Dump the topping onto the fruit mixture and bake for 50-60 minutes until the top is golden brown.
Serve with heaping scoops of vanilla ice cream on top.
Notes
Heads up – a lot of people call for their peaches to be peeled when baking with them, but peeling peaches is a total pain in the butt and I actually don’t mind the skin. That said, feel free to peel your peaches if that’s more your jam.