The best chocolate cake around. Seriously.

CHOCOLATE SOUR CREAM CAKE

2 1/4 oz natural cocoa (not Dutch processed) (Note: I didn't weigh the cocoa, but I estimated just over 1/4 of the 8-oz. box, dumped out that much in the bowl, and that seems to have been the right amount.)
6 oz bittersweet chocolate, chopped very fine or grated
1 tsp instant espresso powder (Note: I used a heaping tablespoon of instant coffee)
3/4 cup boiling water
1 cup sour cream, room temp
8 3/4 oz (1 3/4 cups) unbleached all-purpose flour
1 tsp salt
1 tsp baking soda
12 tablespoons (6 oz) unsalted butter, room temp
14 oz (2 cups) packed light brown sugar (Note: I ran out of brown sugar and had to substitute about 1/4 c. white sugar. It turned out fine, but don't substitute too much.)
1 tablespoon vanilla extract
5 large eggs, room temp

Heavy cream for whipping, and raspberries (optional, but highly recommended)

1. To line the pan, either use some fancy-dancy "cake release spray" or do it like the America's Test Kitchens people did. Melt some butter and dump some cocoa in it until it looks good enough to pour on anything you can think of. Do NOT attempt to taste this mixture, no matter how good it looks or smells. You'll spend the next several minutes hacking and spitting, and your faith in chocolate will be shaken. Use a fancy-dancy "pastry brush" or a little paintbrush you bought several years ago and have to monitor for shedding bristles now and then to paint the inside of the bundt pan. This is so the outside of the cake doesn't have the bitterness of the butter-and-flour method, or at least that's what I remember the America's Test Kitchens people saying.

2. Grate or chop the chocolate. This takes a while, and one gets bored, so make sure the radio is on with a really interesting interview or something. I would suggest making this cake around 1 to 2pm, when Fresh Air is on.
Preheat the oven to 350, and put the rack in the lower third of the oven.

3. Put the 3/4 c. water on to boil. Dump the cocoa, chopped/grated chocolate, and espresso powder in a medium heatproof bowl (I used my smaller stainless steel mixing bowl). When the water boils, pour that in and whisk the hell out of it until it looks smooth and yummy. Again, do NOT attempt to taste this, for the reasons mentioned above. The original recipe says to set it aside to cool it to room temp, but I just set the bowl in my bigger stainless steel bowl with some ice water and stirred it there for a minute or so. When it cools to room temp, whisk in the sour cream until it's all incorporated and a lovely creamy brown color.
In another bowl, whisk together the flour, salt, and baking soda. You could do it in a sifter, but you have to do the whole dry ingredients-wet ingredients-dry ingredients-wet ingredients thing so it's easier if it's in a bowl.

4. If you're not as stubborn as me, and you don't love your whisk like I do, go to the mixer with the butter, sugar, and vanilla, and beat that together until "pale and fluffy," although I have to say I don't think I've ever seen this mixture become particularly fluffy. Maybe I'm missing something. The recipe says to beat it in the mixer for about 3 minutes. I think this translated to 5 minutes by hand, but I just beat it until the mixture was consistent and the color I was thinking of painting the dining room at one point. How's that for precision? If you're using a mixer, reduce speed to medium and add the eggs one at a time, incorporating them fully after each addition. If you're using your arm and a whisk, disregard the instructions about speed and add the eggs one at a time, incorporating them fully after each addition.

5. If you're using a mixer, make sure you scrape the sides of the bowl down so you don't get chunks of unmixed ingredients in the finished product. Add 1/3 of the flour mixture and incorporate it fully; add 1/2 of the chocolate mixture and incorporate it; repeat with another 1/3 of the flour; the other half of the chocolate; and the remaining flour. Don't overmix--mix just until it's consistent throughout, and then stand back and see how pretty the finished batter is. You're in safe territory as far as tasting at this stage, unless raw eggs in the batter turn you off (I personally don't have a problem with this, having eaten my weight in cookie batter over the years).

6. This is a thick batter, and pouring into a bundt pan is usually a pain in the neck. I found that scooping it out one spatula-full at a time worked better than trying to pour around the circle. To get rid of air bubbles or whatnot, pick up the full pan and thunk it on the counter a few times. Stick it in the oven and go do something else for 45-50 minutes. Do the wooden skewer test to check for doneness. When you're satisfied that it's not still liquid on the inside, put an upside-down cooling rack on the top and flip the pan over to cool for a couple hours or so, after which point the cake should pop right out of the pan.

7. Fresh whipped cream is so good, and so easy you shouldn't even think of doing the Cool Whip thing, and ice cream is just way too heavy and sweet for this cake. My years of experience (torture) in the kitchen at 15th & Olive on dessert duty taught me that the quickest, easiest, and best way to go about it is to take a stainless-steel bowl of a size that allows you to move the whisk around in heavy cream of sufficient depth (not more than 1/2" or so or else you'll be whisking all night), stick that in a larger bowl with ice, and whisk away. Cream that's too warm won't peak like it should. You're not so much stirring as beating--the goal is to get air into the cream so this part of the process creates a racket, especially if you're using a metal bowl with a metal whisk. Once you get some volume, but not stiffness, sprinkle in some powdered sugar and continue whisking. You should add a little at a time and taste along the way. It can get really sweet really quickly. Cut a slice of your cake, dump a dollop of whipped cream on it, and throw some raspberries on top. A sprig of mint looks awful purty on top, and if you have mint growing anywhere around your house, you can undoubtedly spare a sprig or fifty.