Pop your buttermilk pie in the oven at 400 degrees for 10 minutes to start, then lower the oven temperature to 350 degrees and bake the pie for another 30 to 40 minutes. Watch the pie carefully for the last 10 minutes or so; you want the pie to be golden brown and for the pie filling to set, which means it may be a bit jiggly in the middle, but not liquid. Watch the crust, too; if it gets too brown, cover it with foil for until the pie has finished baking.