Add the cereal to a large container (with cover) or a 2-gallon Ziploc bag, set aside.
In a medium microwave-safe bowl, melt the chocolate chips, butter, and peanut butter together at 30-second intervals, stirring between each one until melted and smooth. Stir in the marshmallow fluff until fully incorporated.
In a separate large mixing bowl, whisk together the hot cocoa mix and powdered sugar.
Add the chocolate and peanut butter mixture to the bag with the cereal. Seal the bag and shake until the cereal is fully coated.
Then add the powdered sugar mixture to the bag, seal, and shake until fully coated.
Place two wire racks on two large baking sheets and spread the muddy buddies out to cool. Allow them to cool for about 30 minutes.
Transfer the muddy buddies to a bowl and stir in the Sno-Caps and mini marshmallows. Store for up to 2 days in an airtight container.
Notes
You'll need 1.5 to 2 ounces of hot cocoa mix. Depending on the size of the packets you buy, this may be 1 or 2 packets. If you have a bulk can of hot cocoa mix, you'll need about 6 tablespoons.