Preheat the oven to 350°F.
Butter and flour two 8 x 2 inch round cake pans and add a parchment round to the bottom of each pan. Set aside.
Mix together the boiling water and cocoa powder until the cocoa powder is completely dissolved. Set this aside.
Melt the semi-sweet chocolate with the heavy cream and allow it to cool slightly while you prepare the rest of the ingredients.
In a mixing bowl, cream together the butter and and both sugars until light and fluffy. This usually takes around 3-5 minutes.
Beat in the eggs one at a time stopping to scrape the bowl and beaters as needed.
Add the vanilla and the water-cocoa mixture. Continue to beat for another 2 minutes until the ingredients are combined.
In a separate bowl, sift together the dry ingredients.
Add the dry ingredients to the mixing bowl alternatively with the buttermilk. Add about one quarter at a time starting and ending with the dry ingredients.
Beat the batter together making sure you stop to scrape the sides of the bowl periodically so all of the ingredients are fully incorporated. Don't be tempted to over mix the batter.
Add in the melted semi-sweet chocolate and mix well.
Separate the batter evenly among the prepared pans. Drop the cake pans a couple of times on the counter to remove any trapped air bubbles.
Bake for 32-35 minutes or until a toothpick inserted into the middle comes out clean.
Allow the cake to cool almost completely in the pans.
Then remove the baked layers to a wire rack before icing.
Ice as desired.