Preheat the oven to 400 degrees F (200 degrees C).

Mix flour and sugar in a food processor. Cut in butter until mixture resembles coarse bread crumbs. Stir in egg until pastry is well blended.

Press 1/2 the pastry mixture into the bottom and up the sides of a 9-inch pie pan, pushing firmly to make an even layer. Reserve remaining pastry mixture to sprinkle on top of filling.

Mix berries, sugar, and flour in a bowl until well blended. Spoon filling into bottom crust. Sprinkle reserved pastry mixture on top of fruit.

Bake in the preheated oven for 15 minutes. Reduce temperature to 350 degrees F (175 degrees C) and bake until top is golden brown, 45 to 50 minutes more.