This is the best cake from scratch I've ever made. Seriously. To me, it has the exact texture that a light cake should have (as opposed to those cakes that you want to be dense or have a larger crumb - carrot cake, almond meal cakes, and such). I would even describe the texture as tender, while holding shape well and having good flavor. And it's more chocolaty than most German chocolate cakes, which makes me an even bigger fan.
I would attribute its texture to the buttermilk and the whipped egg whites that you fold into the cake flour-based batter, and its flavor to the melted chocolate AND cocoa powder that you add in (see this post for a helpful explanation of the differences between Dutch processed and natural cocoa powder). Thanks to David Lebovitz for posting this great recipe!
I would use my mom's traditional coconut pecan frosting recipe rather than Dave Leb's chocolate version, because hers has this buttery flavor and thick consistency that you just can't beat. I haven't tried making this batter into a layer cake, but it's worth trying. This cake with that frosting is a dynamite combination!
German Chocolate Cupcakes
2 oz (60 g) bittersweet or semisweet chocolate (less than 60%), chopped
1/4 C (60 ml) boiling water or coffee
8 T (4 ounces, 115 g) unsalted butter, at room temperature
3/4 C (150 g) sugar
2 large eggs, at room temperature, separated
1/2 tsp vanilla extract
1 C plus 1 T (150 g) cake flour (not self-rising)
1 T unsweetened natural cocoa powder
1/2 tsp baking soda
1/2 tsp salt
1/2 C (125 ml) buttermilk,* at room temperature
1. Preheat the open to 350ºF. Line a muffin tin with 12 cupcake liners.
2. Pour the boiling water or coffee over the chocolate, and stir until melted. Set aside.
3. In the bowl of a stand mixer, or by hand, beat the butter and sugar until light and fluffy.
4. Add the egg yolks and mix until thoroughly incorporated. Then mix in the vanilla and the melted chocolate.
5. Whisk together the cake flour, cocoa powder, baking soda, and salt. Stir half of the dry ingredients into the wet mixture, then add the buttermilk, then the remaining dry ingredients, mixing just until blended.
6. In a clean, dry bowl, whip the two egg whites until stiff, then fold one-third of them in to the chocolate batter, then the rest. Fold just into there are no streaks of white remaining, but don't overfold.
7. Divide the batter between the muffin cups and bake for about 25 minutes, until the batter feels just set in the center. Remove from the oven, then let cool for a few minutes.
Once cool enough to handle, remove the cupcakes from the muffin tin and let cool on a wire rack completely before frosting.
Coconut Pecan Frosting
1 C evaporated milk
1 C sugar
3 egg yolks
1/2 C butter
1 tsp vanilla
1 1/3 C angel flake coconut
1 C chopped pecans
Combine in a medium saucepan. Cook and stir over medium heat until thickened, about 12 minutes (if it's taking longer, turn up the heat slightly).
Add coconut and pecans.
Beat until thick enough to spread. Makes 2 1/2 C.
*David Lebovitz adds this note: For those of you who can't get buttermilk, you can use a similar quantity of whole milk plain yogurt or sour cream, Or mix 1 1/2 teaspoons of vinegar or lemon juice with 1/2 cup (125 ml) whole milk and let it sit 10 minutes.