Add marshmallows and stir occasionally until 75% are melted.
Remove from heat and continue stirring until all the marshmallows are melted.
If your pot is large enough, you can stir Cap'n Crunch right in. If not, dump cereal in a large bowl and pour melted marshmallows over.
Stir until everything is evenly coated.
Dump your treats in a large buttered pan, a 16"x 9" baking dish will work. Wet your hands and use them to gently spread treats into an even layer. (Don't push too hard or treats will compact and be hard and dense.)
Let sit a room temp for about 1-2 hours until set. Cut into 32 pieces and enjoy!