Preheat your oven to 350°F (175°C) and generously butter a large cast-iron skillet.

In a large mixing bowl, combine the cooking apples, fresh cranberries, granulated sugar, flour, salt, and lemon juice. Toss until coated and transfer to the skillet, dotting with pieces of cold butter.

In the same bowl, mix together the topping ingredients until combined, then add the softened butter and work it into clumpy crumbs.

Take handfuls of the topping and scatter it over the fruit filling to cover, leaving some fruit visible.

Bake for 40-50 minutes until the topping is golden brown and juices are bubbling. Let cool for at least 10 minutes before serving.

Serve warm or at room temperature, optionally with a scoop of vanilla ice cream.