Preheat oven to 300 degrees and prepare a rimmed baking sheet by lining with parchment paper. In a small bowl, combine the almond butter (or coconut butter, soften in a warm water bath or over heat of preheated oven, if needed), maple syrup, and cinnamon/vanilla, if using. Stir well until fully combined. Pop the popcorn (see note), collecting on the lined baking sheet. Transfer about half of the butter/sweetener mixture to a large bowl. Add about half of