Melt one stick of margarine in a large microwave safe bowl. You could use an aluminum foil bowl if you wanted to light up your life and destroy your kitchen, but I wouldn't recommend that.
Mix the miniature marshmallows into the melted margarine, zap in microwave for 1 minute.
Grease up a 12x17 sheet pan, if you don't have one of these, use whatever you have, size will not matter, do not worry over this, we much bigger things to fuss over.
I melted these at about 1 minute in the microwave, give them a good stir, if those little suckers are still lumpy, give them another 30 second zap to finish them off.
Add 8 cups of krispie rice cereal to the lovely melted marshmallow and margarine mixture.
Using clean, buttered paws or hands, press warm cereal mixture into buttered pan. Aah glorious melted fat.
The warm krispie and marshmallow mixture in pressed into a buttered pan, and please allow it to cool or rest for about 15 minutes before dumping it out. You can now lick your gooey fingers.
Cut the big rectangle into two even sides, you could use a ruler if you are OCD or just eyeball it, you can make it match up by squishing it a little, this is also the time to smooth that beautiful brown caramel onto one side of the layer. You do not have to heat the caramel, just use it at room temperature and it will work great.
Flop the un-carameled side onto the carameled side, gently press together, and allow them to form a bond that can never be divided.