Position an oven rack in the middle of the oven. Preheat the oven to 350°F (180°C). Grease an 8x8 or similar-sized, oven-safe dish.
Make the crumble topping by mixing the flour, brown sugar, cinnamon, and nutmeg in a bowl.
Break the cold butter up into slices or smaller pieces. Cut the butter into the dry mixture until it forms a crumbly texture. You can use a fork or pastry cutter for this.
Stir in the pecans. Place the crumble topping in the refrigerator for now to keep the butter cold.
Dice the pears into bite-sized pieces or slices. Add pears, maple syrup, vanilla, and cornstarch to a large mixing bowl. Gently stir them to fully coat the fruit.
Place the pear filling in an even layer in the dish. Try not to include any of the pear juice from the bottom of the bowl.
Scatter the crumble topping onto the pears in an even layer all the way to the edges of the dish. Don’t pack it down as we want it to be light and airy.
Bake the dessert on the middle rack for about 45 minutes or until it’s golden brown and bubbling. Let it cool for 10 minutes and enjoy!