I used two german chocolate cake mixes (for most basic cakes, cake mixes are as good as any made from scratch recipe I've found, my great grandmother agreed with me…) and baked them in four 9 inch round pans. One set of cake pans have a removable bottom making it easy to get cakes out. My other pans are tradition round cake pans, so I use coffee filters flattened in the bottom along with cooking spray, and the cakes came out perfectly.
Once the cakes were cooling on a rack, I started making the mint mousse. I based it off the strawberry mousse recipe I love to use. Instead of pureed fruit, I used whole milk, two or three drops of green food coloring, and 7 drops of peppermint oil to mix with the gelatin. Once that began to thicken, I folded it into my whipped cream. I think next time I will use cream, as this mousse was very light and airy, which went well with the heavy chocolate ganache, but I think cream would make it a little more finished.
I chilled the mousse in the fridge for half an hour and then spooned it onto my two bottom cake layers (I still only made one recipe of the mousse, because the original cake it was meant for had more layers, and there is plenty).
Carefully place the top layer on the mousse and chill cakes.
While the cakes are chilling, you can start on the frosting. I used my standard buttercream (which means I whip a stick of softened butter until it's light and fluffy, then start adding powdered sugar and a little milk until I get a consistency I'm happy with. For this cake I only used a couple tablespoons of butter and instead added in a block of cream cheese. I think for the amount I made, I could have used two blocks, but the frosting turned out minty and smooth without an overpowering cream cheese flavor. I added five or six drops of green food coloring- I wanted a pale green color- and 7 drops of peppermint oil.
After I frosted the cakes, I put them back in the fridge and started on the ganache. I tried a new recipe, and will be using it in the future.
I doubled the recipe. I actually ended up using a 4 oz bar, and then another 4 oz of imdividally wrapped ghirardeli mint dark chocolates. The mint chocolates gave the ganache just a hint of mint, and it was amazing.
I had a hard time piping mint frosting onto the top of the cake and had to take the bag apart, thin the frosting and start over with a new bag, and in the second attempt, the frosting was softer that I would have liked it, but I didn't want to stop and try again, so I just went with it.
To top it all of I used my cheese slicer to shave Andes mints over the top of the cake.
I wouldn't say it's my most beautiful cake (mostly because the soft frosting didn't stand up well enough on the top, and it's slightly off center), but the pale green is lovely against the chocolate ganache, and the whole thing was incredibly delicious.