Mint and Chocolate Ice Cream Cake

1. Preheat the oven to 350 degrees F. Butter a 9-inch spring-form pan and line the bottom with parchment.
2. Combine the melted butter with the wafer cookies in a medium bowl. Press the mixture into the bottom and almost up the entire side of the prepared pan. Bake for 10 minutes, let cool completely before using.

For the ice cream cake: 

1. Scoop the chocolate and mint ice creams onto the cookie layer, packing it in tightly and alternating the scoops to create a marbled or checkerboard effect. Spread with an offset spatula to make a smooth top. Cover with plastic wrap and freeze until firm, 2 to 2 1/2 hours.
2. Unmold the cake by running a knife around the edge, then unhinge the spring-form and remove. Invert the cake onto a sheet of plastic wrap and remove the bottom of the pan and the parchment. Place a serving plate on the bottom and invert once more (so the cookie layer is on the bottom). Keep in the freezer until ready to frost.

For the chocolate ganache: 

1. Put the chocolate in a medium heatproof bowl. Bring the heavy cream to a simmer in a small saucepan. Pour the cream over the chocolate and stir until smooth. Allow to cool 10 minutes before using.
2. Frost the top and sides of the cake with the ganache and top with the wafer cookies. If the cake begins to get too soft, put it back into the freezer for a few minutes.
3. Freeze another 1 1/2 to 2 hours or up to overnight. Let the cake sit at room temperature for about 20 minutes before slicing and serving.