Sprinkle popcorn with salt. Melt butter in a large pan over low heat. Add marshmallows and chocolate; cook, stirring until melted.
Remove from heat; stir in almonds and popcorn. Shape into balls using a 2-inch ice-cream scoop coated with cooking spray. Transfer to baking sheet lined with parchment paper. Let stand 30 minutes. Can be stored airtight up to 1 day.