Software: butter, Cocoa krispies, 10+ oz. marshmallow fluff (someday I'll compute the oz. of fluff ratio to grams of cereal so I can use the entire box of cereal - geeks help me out here)
Hardware: large microwave-safe bowl, two ramekins or small microwave-safe bowls, blade-type silicone spatula, aluminum foil, non-stick spray (or non-stick aluminum foil), teaspoon-size ice cream scoop, two tablespoon-size spoons, two+ cooling trays that fit in the refrigerator
Put the cooling trays in the refrigerator.
Make the Cocoa Krispie Treats recipe on the box, but with marshmallow fluff instead of marshmallows, and double the butter and marshmallow fluff called for in the recipe. I recommend using 2-3 bags each of both milk and dark chocolate chips: other types of chips, like white chocolate, cinnamon or butterscotch, don't melt or taste right for this recipe. I also recommend doing the math to use all of the marshmallow fluff in the container, and weighing the cereal on a digital scale set to grams (my SWAG is 16 oz. weight of fluff to a typical box of cereal.) Geeks rule.
Get a large microwave-safe bowl and melt the butter. Fold the fluff into the butter with a silicone blade-type spatula. Add the cereal and mix.
Fill ramekins 2/3 full, one with milk chocolate chips and the other with dark chocolate chips. Melt both in the microwave about a minute.
Remove a tray from the refrigerator. Cover the tray with aluminum foil and apply a thin layer of non-stick spray.
Scoop a ball of filling with the ice cream scoop. Drop the ball in a ramekin of melted chocolate. Use a spoon to coat the filling with chocolate. Put the truffle on the foil.
Repeat until the ramekin is empty, fill the ramekin with its type of chocolate, remove the other ramekin, and microwave the chips.
From now on you'll alternate ramekins and keep one ramekin hot in the microwave while you use the chocolate in the other ramekin. Use a sharp knife to mix the chips, as the residual heat will melt the chips. Melt the individual ramekin at about 45 seconds. Adjust the 45-second melting time for your microwave so that every time you remove a ramekin, there are still some unmelted small pieces of chocolate that you have to stir with the knife so that the chocolate melts with carryover heat to avoid burning.
Fill the tray, then place the tray in the refrigerator to harden the truffles.