In a large heavy bottom pot, melt butter. Add marshmallows and cook, stirring frequently, until completely melted. Mix in a small pinch of salt and add the cereal. Stir using a silicone spatula until the cereal mixture is totally combined.
Line a walled cookie tray with a silicone mat such as a Silpat. Working relatively quickly, dump the treats onto the tray and spread across as evenly as possible.
Cover the treats with a piece of plastic wrap and use a rolling pin to gently flatten and distribute the Rice Krispies across the pan. Once cooled, use cookie cutters to cut shapes and set aside.
In a double boiler, melt the chocolate while stirring frequently. Create an assembly line in the following order; Rice Krispies Treats, melted white chocolate, sprinkles, and a cooling rack on a parchment-lined baking tray. Work quickly down the line to avoid hardened chocolate and set the finished treats on the tray to set. Enjoy!