Place the popcorn in a large bowl
In a large pan over medium heat, melt the marshmallows and butter. Stir occasionally until smooth
Pour the melted mixture over the popcorn. Stir with a spatula until the popcorn is coated.
Melt the white chocolate (we popped ours in the microwave for 40 seconds on medium)
Butter your hands to stop the balls sticking
Line a tray with a silicone mat or parchment paper
Begin to form the popcorn into balls.
Dip the tops of the popcorn balls into the melted chocolate and return to the baking sheet.
Allow the chocolate to set before serving.
They will keep for 48 hours in an airtight container.