Start to finish: 25 minutes, plus refreezing
1 pint vanilla ice cream
1/2 cup Marshmallow Fluff
3 Rice Krispies treats (if homemade, about 2-by-3-inches each), cut into small chunks
Soften the ice cream by leaving it at room temperature for 15 to 20 minutes, or microwaving it for 15 to 20 seconds. Once the ice cream is soft, scoop the entire pint into a large bowl. Add the Fluff and mix until it is swirled through the ice cream. Add the chunks of Rice Krispies treats and stir until thoroughly mixed into the ice cream.
Transfer the ice cream to a quart-size food-storage container. Press plastic wrap directly onto the surface of the ice cream, then place in the freezer until firm, about 1 hour.