Melt butter in large saucepan. Add marshmallows and stir until marshmallows are melted, add coarsely chopped candies and stir until candies are just starting to melt. Add cocoa rice cereal r and stir until well coated. Transfer to a buttered 13 x 9 baking dish. Using a buttered spatula press mixture into dish. Set aside.

In a medium bowl, mix together mint extract and vanilla frosting. Stir until combined.

Spread frosting on marshmallow treats. Garnish with chopped solid chocolate candies, optional