Very good! I used semi-sweet morsels and it worked great. I liked the different combination of flavors in this brownie for for a new twist. The peanut butter with milk was a little difficult to spread on the warm brownie, but after a couple of tries, I got it. I was surprised that they stayed together, I thought the marshmallow cream might make them too sticky or gooey, but they stuck together pretty good. I will make these again!