Preheat oven to 200°F and line a baking sheet with parchment paper.
Separate the eggs and add just the whites to a completely clean, dry stainless steel bowl. There can't be any egg yolk in the whites, so separate each egg over a small bowl first if that's easier. Ideally, the egg yolks will be room temperature.
Using a stand mixer or electric hand mixer, whisk the egg whites until they're frothy (about 10-20 seconds).
Add the cream of tartar, maple syrup, vanilla, and optional cinnamon to the frothy egg whites.
Continue whisking until stiff peaks form (about 5 minutes). This step is very important - if the egg whites don't reach stiff peaks, the puffs won't hold their shape.
Sprinkle the powdered peanut butter to the side of the whipped egg whites, not on top of the egg whites.
Very gently fold the powdered peanut butter in with a spatula. Be careful not to knock any air out of the whipped egg whites!
Transfer the mixture to a piping bag or zip-top bag, snip a small hole in the corner, and pipe small puffs onto a baking sheet lined with parchment paper.
Bake at 200°F for 1 and a half hours. Turn the oven off and leave the puffs inside for another 30 minutes to firm up.