Butter a 9 x13 pan

In a large pot (large enough to add marshmallows and rice krispies) melt the butter over medium low heat,stirring occasionally. Once melted, continue to cook, stirring constantly. The butter will foam, the foam will subside a bit, then the butter will begin to go from golden to brown and smell nutty. Make sure you stir up any browned bits that form during the cooking. When it smells nutty and is brown it is done, quickly remove from heat .(The butter can go from brown to burnt quickly so keep a close eye on it and remove from the heat right away.)

As soon as the butter is browned and off the heat, stir in the marshmallows until melted. If you use the large marshmallows or they aren't melting put the pot back over low heat and stir until they are melted.

Stir in the rice krispies and the salt until evenly combined and all the rice krispies are coated.

Scrape them out into the prepared pan and press evenly into the pan with a spatula ( let cool for a minute then sneak a piece and press them again to fill the pan :) )