Make popcorn according to the instructions on the bag.
In a medium saucepan
over medium heat, melt
the butter. Add the marshmallows stirring with a wooden spoon until melted. Add the popcorn
mixing rapidly from bottom to top until well coated. Add the candy coated chocolate, mixing well to distribute evenly.
Butter a 9 by 9-inch baking dish
with butter and line with plastic wrap
. Pour the popcorn mixture into the prepared pan. Press down with the back of spoon and let it cool. Cut in 4 squares and serve.