Preheat oven to 350 degrees. Lightly grease a 9-inch tart pan with a removable bottom. If your tart pan tends to leak when baking, you should also line the bottom with unbleached parchment paper.
Place all crust ingredients in the bowl of a food processor fitted with a metal blade and pulse until nuts are finely chopped. Press crust evenly on the bottom of the pan and into the rim. Freeze crust while you assemble the filling.
In a large bowl gently combine filling ingredients and set aside.
In another bowl, squeeze topping ingredients together with your fingers until the mixture looks well combined, pebbly and no longer dry or dusty.
Remove tart pan from freezer and layer the pears and cranberries on top of the crust. Pour any juices from the bowl on top of the fruit. Spread the crumb topping over the fruit.
Place tart on a baking sheet and bake for 40 minutes or until filling is bubbling and topping is lightly browned. Allow tart to cool slightly before serving. Best eaten the same day it’s made, but if you have leftovers, store in the refrigerator. Do ahead: you can make the crust up to a day ahead and keep it tightly covered in the refrigerator. You can also make the topping a up to 3 days ahead and keep that in a tightly covered container in the refrigerator.