Preheat the oven to 350 degrees.
Spray a 9 x 13 pan with cooking spray and set aside.
In a large bowl combine the brownie mix with the oil, water, and eggs using the directions on the box. You can substitute milk for the water if desired. Mix for 1 minute.
Fold in the chocolate chips.
Pour the batter into the pan and bake according to the package directions (between 25-30 minutes)
Remove from oven and cool completely on a wire rack.
Cut the brownie into 1 or 1 1/2 inch squares.
Put a small dot of frosting on a marshmallow and stick it on top of each brownie.
Heat the frosting in the microwave in 20 seconds intervals, stirring after each interval, until pourable but not too thin.
Spoon the frosting over top of each marshmallow, covering completely. Allow excess frosting to drip down the sides.
Push 2 quins into the frosting as eyes and 1 for the mouth. If you don't have quins place two dots of black frosting for the eyes and 1 dot of black frosting for the mouth.
Allow the frosting to cool and harden for 1 hour before storing in an air tight container or serving.