Now, I'm not as good a baker as our friend, but I can fudge it. (Ha!) I used Jamie's recipe from My Baking Addiction, with a few alterations.
First: I halved the recipe to make a 6-inch, 3-layer cake instead of an 8-inch 3-layer cake. All that high school math served me well (thanks, Mr. Tutland!) as I was calculating to see if a half-recipe would be enough batter; it was close enough for my purposes, so I went ahead with it. I did this because chocolate stout cake is very rich (the "icing" is just chocolate and cream, for heaven's sake) and we were only needing enough for five people . . . and still only ate half of it on the mister's birthday. A 6-inch cake is just enough for a couple of days, without anyone getting sick of cake.
Second: I substituted a mixture of lowfat milk and whipping cream for the sour cream in the original recipe, and didn't notice any lack of richness, taste, or texture.
Third: I left off the decorative chocolate curls and used sprinkles to decorate instead. (And it's kinda pretty, but I wouldn't recommend it. The crunchiness of the hundreds-and-thousands detracts from the experience of the icing.)
So here's the recipe I used. You can find the original here.
Six-Inch Chocolate Stout Cake with Chocolate Ganache Frosting
for the cake
3/4 cup Chocolate Stout (Trader Joe's makes a great one, which I used)
1/4 cup strong black coffee
1 cup (2 sticks) unsalted butter
3/4 cup unsweetened cocoa powder
2 cups all-purpose flour (I used 1 cup whole wheat flour and 1 cup all-purpose)
2 cups sugar
1 1/2 tsp. baking soda
3/4 tsp. salt
2 large eggs
1 1/2 tsp. vanilla
1/3 cup whipping cream
1/3 cup milk
for the icing
1 cup heavy whipping cream
1/2 pound chopped semisweet chocolate (I used chocolate chips)
Directions for the Cake
1) Set oven to 350 degrees F, and grease three 6-inch cake pans. LINE THE BOTTOMS WITH PARCHMENT PAPER. Very important. The cake is very moist, and you'll need the parchment to help get the cake layers out of the pans.
2) Melt butter in a medium saucepan with the chocolate stout and coffee until simmering. Stir in the cocoa powder and whisk till smooth. Remove from heat.
3) Whisk flour, baking soda, and salt in a large bowl.
4) Using your electric mixer (or a lot of elbow grease) beat eggs, vanilla, milk, and cream together, then add the COOLED stout mixture. Add flour mixture and beat on low speed until combined. Divide batter between the three pans. Bake until cake tester comes out clean; approximately 35 minutes. Transfer cakes to cake rack to cool.
Directions for the Icing
1) Simmer the whipping cream in a small, heavy saucepan. Remove from heat and whisk in the chocolate until melted and smooth. Refrigerate until spreadable, approximately two hours.
2) Use a small smear of frosting on the cake plate to stick first layer in place, then spread a small amount of frosting over it. Top with second cake layer, and spread with more icing. Repeat for third layer, then spread remaining icing over top and sides.
I used a stencil cut from parchment paper to get the sprinkles to stick in a specific pattern.
As noted in the original recipe, this cake tastes best fresh the first day, but it can be refrigerated and warmed for leftovers.
Thanks for reading! Enjoy your cake!