In a large bowl, whisk the flour, sugar, and salt together. Add the cubes of butter and use a pastry blender (or two forks) to cut the butter in until it's incorporated and the mixture is coarse, with pea sized pieces of butter throughout.

Add the ice water, one tablespoon at a time, and mix until dough just comes together when pressed. Use your hands to form into a round disc. Wrap in plastic wrap and chill in the refrigerator for 2 hours.

Combine the flour, brown sugar, and salt in a small bowl. Add the butter and use your hands to incorporate. Chill in the refrigerator while you finish the pie crust and filling.

Preheat the oven to 350°F. Remove the pie dough from the refrigerator. On a lightly floured surface, roll the dough out to a 12-inch circle. Transfer to a glass pie plate and crimp or trim the edges.

Toss the frozen berries with the flour, sugar, and lemon juice. Transfer to the prepared crust.

Sprinkle the crumb topping onto the pie. Bake for 60-65 minutes, or until the center of the pie is bubbling and the crumble is slightly golden. Cool completely before slicing.