• Preheat oven to 325 degrees.
• Grease and flour the pans and then line the bottom with parchment paper.
• Mix together flour, baking powder, baking soda and salt. Set aside.
• Melt unsweetened chocolate in the microwave and stir in the sugar.
• Beat in the eggs, oil, buttermilk and vanilla.
• Alternately add the hot water and flour mixture, beat until smooth.
• Divide the batter between the pans.
• Bake at 325 degrees for 30-35 minutes until a toothpick inserted in the center comes out clean.
• Cool the cakes for 30 minutes in the pan, on a wire rack.
• Remove the springform pan sides, peel off the parchment paper and allow the cakes to cool completely on the wire rack.
• Once the cakes are cool, use a large serrated knife to cut off the domes.
• Line the outside of the pan with parchment paper and place one cake in the springform pan.
• Tint 3 cups of vanilla ice cream with green food coloring. Working quickly, spread the ice cream over the cake in the pan.
• Then, the other cake layer and top it with aqua tinted ice cream.
• Put the ice cream cake in the freezer to harden overnight.

Pink Whipped Cream Frosting:

• Before removing the ice cream cake from the freezer, make the whipped cream frosting.
• In a chilled bowl, beat heavy cream until soft peaks form. Add 1 cup of powdered sugar and whip until stiff peaks form. Set the whipped cream aside.
• Beat the softened cream cheese, marshmallow cream, 1 cup of powdered sugar and vanilla until smooth. Fold into the whipped cream. Tint the whipped cream frosting with pink food coloring.
• The next steps need to be done as quickly as possible, because as soon as the ice cream cake comes out of the freezer, the ice cream will start melting!
• Take the ice cream cake out of the freezer, remove the springform pan ring and peel off the parchment paper.
• Quickly cover the top and sides with the whipped cream frosting. Then, use an offset spatula to remove most of the pink frosting (as well as some of the green and blue ice cream, if necessary) from the sides of the cake. You will still be able to see the pink frosting in the cracks.
• Put the cake back into the freezer for an hour or two, to harden. Store the whipped cream frosting in the fridge.
• Once the pink frosting is firm, fill a pastry bag, fitted with a large star tip, with pink whipped cream frosting. Pipe pink swirls around the top edge of the cake and fill the center with white chocolate M&Ms.