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

Place peaches and berries in a colander for about 15 minutes to drain any excess liquid, then transfer to a large bowl. Gently toss with sugar, flour, and cinnamon.

Place one pastry into the bottom of a 9-inch pie pan. Pour fruit filling into pastry, dot with butter, and top with remaining pastry. Cut vents in top pastry and sprinkle with coarse sugar.

Bake in the preheated oven until crust is golden brown, about 45 minutes.