For the Cake:

1. Preheat oven to 350°F. Butter two 8-inch round cake pans (preferably springform for easy removal later), and dust with cocoa powder.
2. In a large bowl, whisk together flour, sugar, cocoa powder, baking soda, baking powder, and salt.
3. Make a well in the center of the dry ingredients. Pour in eggs, hot chocolate, buttermilk, vegetable oil, and vanilla extract. Whisk together until combined. Divide evenly between prepared cake pans.
4. Bake for 30-40 minutes until a toothpick inserted into the center of the cake comes out clean. Cool on a wire rack.

For the Frosting:
Infuse orange peel into cream (optional):

1. Place cream in a saucepan over medium-low heat. Add orange zest to the cream and simmer for 2-3 minutes, until the cream has taken on some orange flavor.
2. Take cream off the heat. Remove zest with tongs or by straining the cream. Discard zest. Allow cream to cool a bit before placing in the refrigerator until completely chilled.

Mascarpone Frosting:

1. With an electric mixer on medium speed, beat cream just until very soft peaks form.
2. In a second bowl, beat together mascarpone and confectioners' sugar until smooth and creamy. Fold orange-scented cream into the mascarpone mixture until incorporated. Frost cake as desired.