01 -  Preheat oven to 350°F (175°C). Lightly grease a 9-inch baking dish with butter. 
 02 -  In a large bowl, toss sliced pears with lemon juice, granulated sugar, ground cinnamon, ground nutmeg, and all-purpose flour until evenly coated. 
 03 -  Spread the pear mixture evenly in the prepared baking dish. Drizzle caramel sauce over the pears. 
 04 -  In a separate bowl, combine rolled oats, all-purpose flour, brown sugar, ground cinnamon, and salt. Add cold, cubed unsalted butter and use a pastry cutter or fork to cut the butter into the dry ingredients until the mixture forms coarse crumbs. 
 05 -  Scatter the crumble topping evenly over the fruit filling. 
 06 -  Place the dish in the oven and bake for 40 minutes, or until the topping is golden brown and the filling is bubbling around the edges. 
 07 -  Remove from oven and let cool for at least 10 minutes. Serve warm, optionally with vanilla ice cream.