In an electric mixer, cream together the butter, sugar and the brown sugar. Add the eggs one at a time. Add the melted chocolate and mix until well incorporated. Scrape the bowl. Add the vanilla and half of the buttermilk. Add the flour and baking soda, mix and finish with the remainder of the buttermilk. Mix until well incorporated. Scoop into baking cups and bake at 350F for about 20 minutes.

Whipped Chocolate Ganache

Bring the heavy cream to a boil and pour over the chocolate. Mix slowly starting from the center until all incorporated and creamy. Let it cool completely for about an hour. Whip until thick.