Have ready a greased 9x13" casserole dish. Combine the mix-in's in a bowl, and set aside until ready to use.
Place a large sauté pan over medium-low heat and add the butter. Once the butter has melted, add the marshmallows and increase the heat to medium-high. Allow the marshmallows to melt down, stirring often. Once the marshmallows have melted, stir in the salt and vanilla extract, followed by the Cocoa Krispie cereal.
Once the cereal is coated in the marshmallow mixture, add in the majority of the mix-in's, reserving about a 1/3 cup for topping. Stir to combine. Transfer to the prepared dish and using your hands (lightly greased with butter), roughly pat out the mixture to form a flat surface. Sprinkle the remaining decals evenly over the dish, and gently pat to set.
Allow the treats to cool completely, about 45 minutes - 1 hour. Then, cut into squares, serve and enjoy!
Makes 12-16 bars.