Whisk flour and sugar together in a medium bowl.
Slice the cold butter into 8 pieces.
Add the butter to the flour and sugar and using a pastry cutter or fork, blend until the mixture resembles little peas.
Sprinkle the crumb topping over the apple and cranberry mixture until covered.
Line the bottom of the oven to catch any spillover from the juices.
Cover the edge of the pie crust with aluminum foil.
Bake for 45 minutes.
Remove foil from edges but cover the top of the pie with foil to prevent the crumb mixture from burning.
Bake the pie for 15 more minutes until the crust is golden brown and the juices are bubbling in the center.
Cool the pie on a rack and serve at room temperature.