The best, flakiest pie crusts are made thanks to a winning combination of very chilled dough hitting the heat of a very hot oven. As the moisture inside pie dough evaporates, it releases steam, which is responsible for building light, tender layers of dough. Using cast iron means that the pan heats up quickly and retains a consistent temperature throughout baking. Which all adds up to beautifully baked bottom crusts (with no hint of sog).
In short, ditch the pie plate and use a cast iron skillet instead.
Cast Iron Pie-Baking Tips
Baking pies in a cast iron skillet is as easy as any other vessel. I use a No.8 Field Skillet for my recipes, which is the closest in size to a standard pie plate. But here are a few tips you can apply to any cast iron skillet pie: