In a large bowl, pour the corn Chex. Set aside. Place a large piece of parchment paper on the counter for your treats to cool on.
In a medium sauce pan, melt butter until it is half way melted, then add brown sugar and stir. Your butter should quickly finish melting. When it is almost all the way melted, add the marshmellows.
Keep stirring until the marshmellows are fully melted and sauce ingredients are all blended. Do not boil! As soon as they are all melted it is ready.
Immediately pour onto the corn Chex in your large bowl and stir well to coat. This will take a minute or two because this is a sticky sauce, but stir quickly so that it doesn't start to set before you are able to scoop it onto clusters.
Using a large cookie scoop(I use pampered chef size large), quickly scoop your Chex mixture onto parchment paper in clusters. This is a bit of a sticky process due to the marshmellows, but only takes a few minutes.
Let them cool completely so they will stick together. This takes about 7-10 minutes. Store in a zip lock baggie on the counter for 2-3 days. We never have any left after 1 day, so storing them usually isn't a problem.😁
