Preheat oven to 350°F. Grease a 2-quart baking dish or a 10-inch cast iron skillet, or spray with nonstick cooking spray.
Combine the filling ingredients (apples, cranberries, sugar, cinnamon, nutmeg, and salt) in the prepared dish.
In a separate bowl, use a fork (or your fingers) to mix together the butter, flour, oats, brown sugar, sugar, pecans, and salt until completely combined. The mixture will be lumpy and clumpy and should look like a streusel crumb topping.
Spread the topping evenly over the fruit.
Bake (uncovered) for 50-55 minutes, or until the fruit is hot and bubbly and the topping is golden brown. Remove from the oven and let cool for 10-15 minutes.
Serve warm or at room temperature. Top with vanilla ice cream!