In medium bowl, sift cocoa with flour, salt, baking soda and baking powder. Set aside.
In measuring cup, mix coffee and milk together. Set aside.
In mixer, beat butter and sugar for about 5 minutes until smooth. Beat in eggs one at a time. Slowly add in dry ingredients alternating with the coffee/milk blend (I do about 3 additions of each).
Pour cake batter into two prepared pans (two 9inch cake pans lined with parchment paper and then greased and floured). Bake in a 350 degree oven for about 25 minutes. Remove and allow to cool about 10 minutes before removing from pans. Cool completely before frosting.
For frosting, in food processor, pulse dark chocolate until small bits (not powder)! Set aside.
In mixer, beat butter, powdered sugar and milk for 3-5 minutes, until smooth and creamy. Remove one or scoops of frosting, to look like the whipped cream on the cake. Add in extract and food coloring gel to remaining frosting. Mix until fully blended. Add more milk if necessary to desired consistency. Fold in chopped dark chocolate.
Frost first layer of cake, then top it with second layer. Completely frost sides and top of cake. With remaining green frosting, scoop several scoops on top of cake to look like ice cream.
With the reserved white frosting, place in ziploc bag and cut of corner. Pipe onto top of cake to resemble whipped cream.
For the ganache, heat 3/4 cup heavy cream in saucepan. Bring just to a boil and remove from heat. In food processor, pour chocolate chips and slowly add in hot cream and extract. Process chocolate and cream for about 2-3 minutes until completely combined. Pour over chocolate cake and top with a cherry. Enjoy!
Notes
Don't stress about the assembly. I love the look of decorating this like a mint chocolate chip sundae but if you like, you can also just frost it like a regular cake and drizzle the ganache over it. It will still look and taste amazing!
The gel food dye works best for this cake. The liquid dyes or natural substitutes won't be quite the same.
Be sure to use Peppermint Extract, not mint. Mint will taste like spearmint toothpaste.