In a bowl, mix together ricotta and funfetti cake mix until smooth. Spread cheese mixture onto a slice of brioche bread and top with even more sprinkles. Top with the other slice of brioche.
Heat grill to medium-low heat. Spread the butter on each side of the sandwich, and grill for 1-2 minutes, or until the brioche is crispy and the cheese is just starting to melt. Serve immediately.
