Preheat the oven to 425ºF (220ºC).

Combine the peaches, sugar, lemon juice, cinnamon, and flour in a deep bowl. Stir until the flour is mixed in, and juices begin to thicken. Set aside.

Prepare the piecrust.

Roll one crust out into a 10-inch circle. Fit into a 9-inch pie plate (not deep dish). Spoon the filling into the crust.

Roll the remaining crust into a 9-inch circle. Use a small cutter to cut out vents, or cut into strips to make a lattice topping (here's a great tutorial). Arrange the crust on top, flute the edges, or press with the back of a fork.

Bake for 15 minutes. Reduce oven to 350ºF (180ºC). Bake until golden, and juices are bubbly, 40 to 45 minutes.

Let pie cool completely on a wire rack before serving.