In large microwave-safe bowl, microwave marshmallow cream 1 minute at 50% Power. Remove bowl from microwave. Gently stir in popcorn, mixing until evenly coated. Lightly spray hands with vegetable pan spray. Shape into balls or other shape; press mixture firmly into baking cups.
Sprinkle tops with various sugars or sprinkles. If desired, position icing decorations on top.