Preheat the oven to 350°F. In a large bowl, mix together sliced apples, cranberries, granulated sugar, and 3 tablespoons of flour until well combined.
Pour the fruit mixture into a greased 11x7-inch baking dish, spreading it out evenly.
In a separate bowl, combine oats, 1/2 cup of flour, the brown sugar, cinnamon, nutmeg, and chopped pecans.
Pour melted butter over the oat mixture and stir until the mixture is crumbly.
Sprinkle the crumbly topping evenly over the fruit mixture in the baking dish.
Bake in a preheated oven for 50-60 minutes, or until the topping is golden brown and the fruit mixture is bubbling.
Serve warm, with a scoop of vanilla ice cream or a dollop of whipped cream.