In a large bowl, mix together the 5 cups rice Krispie cereal, 16 crushed Oreo cookies and one cup of mini marshmallows.

In a large saucepan over medium heat, melt the 5 Tbsp of butter.

Add the remaining 8 cups of mini marshmallows and salt and stir into the melted butter. Continue stirring over medium heat until the marshmallows are completely melted into the butter.

Spread the Oreo Krispie mixture into a 9-inch square pan and press gently with the spatula to flatten the top.
Allow the Oreo Krispies to cool in the pan for about 30 minutes before slicing and serving.