To make ganache frosting, pour baking chips into a large, heat-safe bowl. Bring heavy cream to a simmer in a small saucepan over medium-low heat, stirring frequently. Once cream begins to bubble and steam, remove from heat and pour over baking chips. Place a clean kitchen towel over the bowl, and allow to sit undisturbed for five minutes.
After five minutes, remove towel and begin to stir ganache slowly with a whisk. Continue whisking until smooth and velvety.
At this point, you can use the ganache right away if you want a simple glaze. If you want a whipped frosting, however, the ganache needs time to cool and thicken. Allow the ganache to thicken on the counter at room temperature, and after about 2 hours it should come out looking like this.
While ganache is cooling, begin making cupcakes. Preheat oven to 350 degrees. Line two muffin tins with cupcake liners and set aside. In a large bowl, combine flour, sugar, cocoa powder, salt, baking soda, and baking powder. Mix well.
Add in vanilla, eggs, buttermilk, and vegetable oil mixing until smooth. Pour in hot water and mix well. Batter will be very thin.
Pour batter into prepared cupcake liners, about 2/3 full. Bake in preheated oven for 16-18 minutes, or until a toothpick inserted in center comes out clean. Allow to cool completely on a wire rack.
Once ganache has thickened, beat over medium speed with an electric mixer until frosting is lighter in texture and color, about 3-4 minutes.
Frost cupcakes with a piping bag or simply dollop on with a spoon. Top with decorations of your choosing if you wish. I used some sprinkles and fun Ghirardelli Valentine's Day Impressions chocolates. Enjoy!