This is a long standing, often eaten, sweet in our house. The difference being that I use real butter, one more Tbs. than the recipe calls for and the entire package of marshmallows, along with the six cups of Rice Krisp cereal. I also use butter to grease the pan or the butter paper.
Try it, better than the recipe, I might say.
The recipe is on the side of the cereal box, or can be found online, just change it a bit.