Preheat the oven to 350°F. Butter a 9x9-inch baking pan.
Combine all of the filling ingredients in a bowl. Set aside for 10 minutes, stirring occasionally.
Combine the flour, brown sugar, cinnamon, and salt in a food processor and pulse briefly to mix. Scatter the pieces of butter over the dry mixture. Pulse several times, or until it has a sandlike consistency.
Transfer to a large bowl and rub the mixture between your fingers until it is uniform and clumpy.
Spread the fruit in the prepared pan. Sprinkle with the topping.
Bake on the center oven rack for 45 minutes, or until the apples are soft and the cranberries are bubbly.
Transfer to a cooling rack for at least 10 minutes before serving.