Preheat oven to 300 degrees F. 

In small microwave safe bowl, combine butter and honey. Microwave on high power 2-3 minutes, stirring every 30 seconds, until mixture boils and butter is melted. Watch carefully to make sure mixture does not overflow. 

In large bowl, combine cereal, cashews, and sunflower seeds. Pour honey mixture into bowl and stir well to cover completely

Spread mixture onto a large foil-covered rimmed baking sheet. Bake uncovered 25 minutes, stirring halfway through.

Pour out onto sheet of waxed paper to cool completely. Once cool, add in M&M chocolate candies.