Pour hot mixture over chocolate chips in a medium metal bowl, and stir until chocolate is melted. Place chocolate mixture in bowl in a ice bath, and stir until frosting hardens a bit. Take out of ice bath and whip with a beater until it is light and fluffy.
Now’s the time to ‘decorate’ the cake, or just frost it. As I mentioned before, there is a great class on Instructables making a great cake, particularly the decorating. See that class here.
It was a really helpful class, and here’s my own instructions on how to ice the cake:
If you haven’t yet, level the rounded tops of the cake layers so that they are flat, with a knife.
Start with the first layer of cake.
Put some of the frosting on top of the center. With your knife angled outwards, turn the cake platter, and push the frosting gradually out, until there is a smooth circle of frosting on the top of the cake.
If you want to, as I did, you can smash some fruit like strawberries, or raspberries in between layers, as in picture.
Place the second layer on top of it. Repeat the process as described above.
Then put on the last layer of cake. Then ice the rest of the cake, sides, and top, making sure to reserve a good bit of icing for going over the cake again. The first layer you just put on is the ‘crumb’ layer, and after cooling it in the fridge for 20 minutes or so, you should have a nice solid cake to put the last layer of ganache on.
A cake frosting knife as shown in pic is very helpful in this situation. After applying the final layer of ganache, refrigerate for another 20 + minutes, and then take out of fridge.
Now, if you want to, you can do something extra that will probably make your cake look smoother and nicer.
Run your cake knife over really really hot water for about fifteen seconds, then quickly dry it with a paper towel, and run the hot knife smoothly over the cold ganache. Repeat this a few times until you have a smooth frosting.
Store in fridge, completely plastic wrapped to keep it from drying out.
To see full step-by-step pictures for this recipe, go to my original post on instructables.