Peanut Butter Custard Pie with Marshmallow Whipped Cream

Baked custard pies were all the rage a century ago and remind me of what we call “pudding” or “cream” pies, save for the fact that a custard pie has no thickening agent and is baked. Here, I have fiddled with the Cup Custard recipe from Baker’s Pure Fruit Flavoring Extracts (no date), by adding cornstarch and cooking it over the stove (as opposed to in the oven). I then added plenty of creamy peanut butter, kosher salt, and vanilla to ensure that this