Put the dairy-free spread, brown sugar, and marshmallows in a microwave-safe bowl OR a saucepan.
If microwaving the mixture, cook at 1-minute intervals, stirring after each minute, until the mixture is melted and smooth.
If cooking the mixture on the stove top, heat the saucepan over low heat and stir the mixture until it is melted and smooth.
Stir the peanut butter or seed butter into the marshmallow mixture until it is well blended.
Immediately pour the marshmallow mixture over the popcorn and stir quickly before it cools.
Gooey peanut butter popcorn option: Serve the popcorn once it is cool.
Peanut butter popcorn bars option: Press the popcorn mixture into a greased 9x13-inch pan and cut into bars once cool.
Crunchy baked peanut butter popcorn option: Spread the popcorn onto a foil-lined cookie sheet. Bake at 200ºF for 20 to 30 minutes, stirring every 10 minutes, or until crisped to your liking.
Recipe by Go Dairy Free at https://www.godairyfree.org/recipes/peanut-butter-popcorn