I have a pumpkin pie recipe that calls for an unbaked pie shell. During the cooking step, it cooks first at 425°F for 15 minutes, and then at 350°F for 30-40 minutes (until toothpick can be inserted cleanly). My understanding is that the first bit of cooking, at 425°F is to finish off the (frozen) crust, and then the 350°F is to cook the filling through.
At the moment, I have no unbaked pie shells, but I do have some graham cracker crust pie shells that I would like to substitute in their place. I figure that since the shells are 'ready to eat' already, they don't need the initial 425°F cooking step. Since the pumpkin still needs to cook and set, I would need to somehow extend the 350°F step accordingly to account for the cooking done in this initial stage, if I omit the 425°F step.
My basic plan is to fill the crusts and then bake at 350°F for about 50 minutes. Then continue baking until it passes the toothpick test (checking every 5 minutes or so.)
Is this a reasonable plan, or should I instead retain the 425°F initial baking phase even though the crust itself doesn't require any cooking? Or are the graham cracker crust shells entirely unsuitable for this project for some reason I'm overlooking?
(I'm following the basic Libby's "new fashioned pumpkin pie" recipe, which I've used previously many times with frozen pie shells.)