Before starting, place the bag of mini marshmallows in the freezer for at least 5 minutes.
Place a large pan over medium-low to medium heat. Add the butter, peanut butter, and chocolate. Melt and blend the ingredients stirring often.
Remove the pan from the stove and let cool for about 5 minutes.
While the chocolate mixture is cooling, prepare an 8 x 8-inch or 9 x 9-inch pan by lining it with parchment paper.
When the chocolate has cooled for about 5 minutes, stir in the crispy rice cereal and 3 cups of mini marshmallows. Stir quickly and just enough to keep the mini marshmallows from completely melting.
Pour the rocky road bars mixture into the prepared dish. Spread evenly and top with the remaining marshmallows.
Refrigerate the bars until fully set, about 2-3 hours.
Lift the whole chocolate out of the pan. Cut the rocky road into squares or bars. Serve and enjoy!
Notes
By cooling the marshmallows first, they will not melt as much when you are mixing together the rocky road ingredients.Parchment paper will make it easier to get the rocky road candy out of the pan later. Make sure some of the parchment paper is allowed to come up over the sides of the pan so you have something to grab onto.