My Mother in Law makes these and they are so wonderful. Love them.
1 box of brownie mix (prepared to package directions)
1 bag mini marshmallows
For the Frosting:
1 cube butter, melted
1/4 cup cocoa
t Tbs vanilla
1/2 bag powdered sugar
about 1/4 cup evaporated milk (add until it comes to the right consistency)
Bake brownies according to the directions on the box. Once the brownies are done. Turn on the broiler on the oven. Place the marshmallows on top of brownies and melt them under the broiler (this only takes seconds, so watch carefully)
Make the frosting by adding all of the ingredients in a bowl and mixing until smooth. Once brownies have cooled a bit, frost.