Prepare my Pie Crust Recipe and divide the chilled dough in half. Place one half in the fridge or freezer for later. Continue directions all the way through to lining the 9 inch pie dish and placing in the fridge to chill and firm while you prepare the filling.
Raspberry Pie Filling
Place raspberries a large bowl and add flour, sugar, cornstarch, lemon juice, and vanilla. Gently stir with a rubber spatula until berries are evenly coated.
Set bowl in the fridge while you prepare crumble topping.
Preheat Oven to 400 F.
Crumble Pie Topping
Stir together ingredients in a medium bowl using a fork and set aside.
Make the Raspberry Crumble Pie
Remove chilled pie crust from fridge and scoop raspberry filling into crust. Gently level berries.
Sprinkle crumble topping across the pie filling.
Place pie in oven on middle rack and bake for 25 minutes.
Reduce heat to 375 F and bake for an additional 30 minutes until edges of crust and top of crumble are golden brown and filling is bubbling. (I also cover my pie with a loose fitted sheet of aluminum foil when I reduce the heat to prevent over browning.)
Remove pie from oven and place on a cooling rack for at least an hour before slicing to allow filling to thicken.
Serve with vanilla ice cream!
Cover pie with aluminum foil and store in fridge for up to 5 days.