For the Chocolate Crumble Topping
In a large bowl add the flour, brown sugar, cocoa powder and salt and lightly mix together. Add the cold butter and using your fingers (or a dough cutter) rub in the butter into the dry ingredients until the mix resembles coarse breadcrumbs. You can also use a food processor for this step. Mix in chopped chocolate. Set aside in the fridge until ready to bake your crumble.

For the Pear Filling
Preheat the oven to 350ºF (180ºC). Set aside a 9-inch baking dish. You want a wide and shallow dish for this recipe as there are lots of crumble toppings. Peel, core, and chop the pears into chunks. (It's very important you use ripe pears so they will soften while baking.) In a bowl mix the pears together with the cornstarch and lemon juice. Pour filling into the baking dish.

Top with the chocolate crumble mixture distributing evenly. It will look like it's too much but it's fine. It will bake down. Bake for roughly 45 to 50 minutes or until the pears are soft and the topping is baked. Serve warm with vanilla ice cream. Any leftovers can be stored in the fridge for up to 4 days.