Line the bottom of a 9x13" baking pan with parchment paper. Set aside.
In a large pot, melt butter over medium high heat then pour in the bag of marshmallows. Stir continually until the marshmallows have all melted. You need to stir frequently to keep the marshmallows from burning.
Remove pot from heat and pour in the corn pops cereal. Mix/stir until all the corn pops are covered in the marshmallow mixture. If you feel that you need more cereal, add more, a 1/2 cup at a time. Like I mentioned above, I like mine more marshmallow/gooey.
Immediately pour contents of the pot into prepared baking pan and using the back of a silicone spatula, gently press down on the mixture to evenly spread it throughout the pan.
Let cool for 2 hours then cut into squares.
These are best eaten the day of. By the next day, the cereal gets somewhat stale and soft!