Reduce oven temperature to 350°F.
In a large bowl, combine all the ingredients for the filling. Let set 20 minutes to allow the tapioca to absorb some of the liquid.
Fill the pie shell with the filling and top generously with the crumble topping, pressing it gently into the pie.
Refrigerate for 30 minutes.
Place the pie on a rimmed baking sheet lined with foil. Bake for 45-50 minutes until the crumble topping is golden brown. Cool completely and enjoy with a big scoop of vanilla bean ice cream.