What makes these treats special is not just the fun, colorful sprinkles but the toasty, nutty taste and aroma of browned butter. Letting the butter brown adds another dimension of flavor to this easy dessert.
Melt butter in a saucepan over medium heat, stirring constantly, until it's golden-brown and has a nutty aroma, about 5 minutes. Add marshmallows to browned butter, reduce heat to medium-low and cook, stirring occasionally, until marshmallows are melted, 3-4 minutes.2.
Stir 1 teaspoon sea salt into marshmallow mixture and remove saucepan from heat. Add rice cereal and sprinkles to marshmallow mixture and mix until cereal is evenly coated with marshmallow mixture; transfer to a 9- by 13-inch baking dish.3.
Place a sheet of parchment paper over rice cereal mixture and press into dish. Remove parchment paper. Cool treats to room temperature, at least 30 minutes.