Preheat the oven to 375°F. In a mixing bowl, combine the sliced pears, cranberries, half of the granulated sugar, cinnamon, and nutmeg. Stir until the fruit is evenly coated.
Transfer the fruit mixture to a baking dish and spread it into an even layer.
In the same mixing bowl, stir together the rolled oats, flour, brown sugar, and remaining granulated sugar. Pour in the melted butter and vanilla extract, then mix until the topping forms clumps.
Sprinkle the oat mixture evenly over the fruit. Bake for 35 to 40 minutes until the topping is golden and the fruit bubbles at the edges.
Remove the dish from the oven and let it rest for 10 minutes before serving.