Step 1

Preheat the oven to 375F Butter and flour two 9-inch nonstick cake pans. I like to put a round of parchment paper on the bottom of each one.

Step 2

Put the sugar, chocolate, butter, and the water in a medium to large saucepan and cook, stirring, over medium heat until it all melts together smoothly. Set aside to cool for a few minutes.

Step 3

When the mixture has cooled slightly, whisk in the milk, eggs, and vinegar.

Step 4

Whisk in the baking soda, powder, and salt. Then slowly whisk in the flour, making sure not to over mix...small lumps are fine.

Step 5

Pour the batter evenly into the two pans and bake for about 25-30 minutes, or just until done in the middle and a toothpick comes out without wet batter on it. Be careful not to over bake these cakes.

Step 6

Let cool for about 20 minutes, then turn the layers out onto a rack to cool completely before frosting.

Step 7

Cook cranberries, sugar, and a splash of water in a saucepan on medium heat until the cranberries break down and into a thick, juicy mixture. This will only take about 5 minutes.

Step 8

Puree the cranberries in a high speed blender, preferably, or a food processor until perfectly smooth. Chill.

Step 9

Put the soft butter, sifted sugar, cream of tartar, and 1/2 cup of the cranberry puree (you will not need it all) into the bowl of a stand mixer fitted with the balloon attachment. Beat, scraping down the sides often, for about 4 minutes, until light and fluffy. Add more sifted sugar if you want a stiffer buttercream.

Step 10

Frost the cake, and then refrigerate until ready to serve. Keep chilled.