Step 1: Preheat your oven to 375°F (190°C). Lightly grease an 8x8 inch baking dish.
Step 2: In a large bowl, combine the diced pears, grated fresh ginger, 1/2 cup brown sugar, cornstarch, 1 teaspoon cinnamon, 1/2 teaspoon nutmeg, and 1/4 teaspoon salt. Toss gently until the pears are evenly coated.
Step 3: Pour the pear mixture into the prepared baking dish and spread it evenly.
Step 4: In a separate medium bowl, combine the rolled oats, all-purpose flour, granulated sugar, 1/4 cup brown sugar, 1/2 teaspoon cinnamon, and 1/4 teaspoon salt. Whisk to combine.
Step 5: Add the cold, cubed butter to the dry ingredients for the topping. Use your fingertips or a pastry blender to cut the butter into the mixture until coarse, crumbly pieces form. Some pea-sized butter pieces should remain.
Step 6: Sprinkle the crumble topping evenly over the pear filling in the baking dish.
Step 7: Bake for 35-45 minutes, or until the topping is golden brown and the pear filling is bubbly and tender when pierced with a knife. The exact time may vary based on your oven and the ripeness of the pears.
Step 8: Remove from the oven and let cool for at least 10-15 minutes before serving. This allows the filling to set slightly. Serve warm with vanilla ice cream or whipped cream. Enjoy this delightful addition to your pear dessert recipes repertoire!