First, prepare a 9x13 baking dish. Cut a piece of parchment long enough to hang over the sides of the dish, then spray the inside with a light coating of cooking spray and set aside.
In a large nonstick pan or pot, melt the butter over medium heat on the stove.
When the butter is melted, reduce the heat to low and add the marshmallows and salt.
Stir slowly until the marshmallows are completely melted into a thick, gooey sauce, then stir in the vanilla extract.
Remove the pot from the heat and pour in the rice cereal.
Fold the rice cereal into the marshmallow cream until the mixture is completely coated and mixed throughout.
Spoon the mixture into your prepared parchment-lined baking dish and use the back of a spatula (or the palms of your hands) to press the mixture into an even layer into the dish.
Allow the mixture to cool to room temperature, then press cookie cutters into the rice treats to cut out shapes. Set them aside on a piece of parchment until you’re ready to decorate them..
To decorate the treats:
In a large microwave safe bowl or tempered glass measuring cup, microwave the white chocolate intervals of 20 seconds until completely liquid and melted.
Stir the coconut or vegetable oil into the melted chocolate to make it nice and smooth.
Dip one side of each rice treat into the white chocolate and let any excess drip back into the bowl. You may need to dip twice to get a good coating.
Immediately dip or spoon sprinkles over the white chocolate and place the treats decor-side up to rest and allow the white chocolate to harden and set.
Notes
Pro tip: To make pressing the Rice Krispie treats into your baking dish, spray a silicone spatula or the back of a mixing spoon with cooking spray to keep the mixture from sticking. You can also spray your cookie cutters before pressing them into the Rice Krispie treat slab. You may have to do it between each time if you find that the marshmallow is sticking to the cutter too much. These treats will stay yummy for 4-5 days in an airtight container left at room temperature on the counter.