Preheat oven to 350F and prepare two 8" or one 9x13" pan.
Either melt in double boiler (or mix up from cocoa powder like I did) until smooth
3oz unsweetened chocolate
and set aside for now.
Sift into a large bowl:
1 3/4 cup cake flour (if you don't have cake flour, scoop a cup of all-purpose flour, remove 2 TB of the flour, then add 2 TB of cornstarch per cup of cake flour called for)
1 1/2 cups sugar
1 Tsp baking soda
1 Tsp salt
Add and beat on high for 2 minutes:
1 cup sour cream
6 TB (aka 3/4 stick) unsalted butter, softened
Then add the chocolate,
2 large eggs
1 Tsp vanilla
1/4 hot water or coffee (I used 1/4 cup of haute chocolate tea from Teavana)
Beat for another 2 minutes and pour into pans, baking until a toothpick comes out clean.
For round pans, 20-25 minutes, for rectangular 25-40.
I didn't bother to frost this, it was so good, but the recipe suggests chocolate frosting, powdered sugar, or serving with whipped cream.
Personally, I'm thinking of serving it with a nice strong chai and fresh whipped cream...