Butter an 8x8-inch baking dish and set off to the side for later.

Add butter to a large skillet and heat over medium heat. The butter will melt and crackle. Once the crackling stops, stir occasionally, and keep an eye out for a light brown color. Once the butter is brown, reduce the heat to low.

Add the marshmallows, puree, cinnamon, and nutmeg. Stir to combine until all the marshmallows are melted.

Pour the brown rice cereal into a large mixing bowl. Pour the marshmallow mixture over the cereal and mix until all the bits are coated. Scoop the mixture into the greased pan, top with pepitas and salted caramel for a little flair. Place in the refrigerator for at least 30 minutes before cutting.