Bake the brownies according to the instructions on the box.
Let the brownies cool completely and then use a 3 inch circle cookie cutter and cut out rounds from the pan of brownies.
You will need two brownie rounds for each tower. Spread frosting on the bottom round and place the top round on top.
Holding the brownie tower sideways over a plate sprinkle the crushed peppermints over the frosting turning the brownie until the frosting is all covered with crushed peppermint.
Place the chocolate in a small bowl.
In a microwave heat the cream in a separate bowl until almost boiling and then pour the cream over the chocolate. Stir until completely smooth.
Pour the ganache over the top of each brownie tower and use a knife to spread it around letting some drip down the sides.