In a large mixing bowl, combine whipped topping, sour cream and instant vanilla pudding mix. Transfer the mixture to a large piping bag.
Lay out the first layer of the cake by arranging chocolate wafers in the base of an 8-inch springform pan. It is fine to have some of the cookies overlap to ensure that most of the surface of the pan is covered.
Pipe 1/4 of the cream over the crackers and spread it out using an angled spatula. Top with a few cherries and cover with the second layer of chocolate wafer cookies. Repeat the layering process until you have four layers in total. Top with the remaining cream and arrange cherries on top.
Make the chocolate ganache: Place the chocolate chips in a bowl. In a microwave-safe bowl, heat the heavy cream in the microwave until bubbly. Pour over the chocolate chips and stir until smooth. Drizzle on top of the cake.
Refrigerate cake for at least 8 hours. Remove the ring of the springform pan and serve.
Not all of the chocolate wafers will be used up.