01 -
Pop the popcorn using an air popper, stovetop, or microwave, and transfer to a large mixing bowl, discarding any unpopped kernels.
02 -
In a medium saucepan over medium heat, melt the butter. Add brown sugar and corn syrup, stirring constantly, and bring to a gentle simmer. Continue cooking for 5 minutes until the mixture is fully combined and smooth.
03 -
Add marshmallows to the saucepan and stir continuously until completely melted and the sauce becomes uniform.
04 -
Pour the warm caramel-marshmallow mixture over the popcorn. Gently toss with a spatula until all popcorn is evenly coated.
05 -
Arrange the coated popcorn in a single layer on a baking sheet lined with parchment paper. Bake in a 250°F oven for 30 minutes, stirring every 10 minutes for consistent coating.
06 -
Remove the tray from the oven and let the popcorn cool completely. Break into clusters before serving.