While that's interesting about chocolate being a fermented food, few of us will ever get the opportunity to ferment cacao at home. What you can do is make a chocolate cake that is moist and rich, yet not cloying or heavy. For Christmas, I received a copy of The Art of Simple Food: Notes, Lessons, and Recipes from a Delicious Revolution, by Alice Waters. The more I cook at home, the more I appreciate simple recipes that highlight the natural flavors of real food, so I have really been enjoying this new book. When my son asked for a chocolate cake for his birthday, I turned to Simple Food for inspiration and was not disappointed.
I did make a few adjustments to ingredients, based on what I had on hand. She called for unsweetened chocolate, but I had a 74% cacao bittersweet chocolate, so I used that and reduced the kind and amount of sugar, from 2 ½ cups brown sugar to 2 cups of Rapadura. Her recipe called for 2 cups of cake flour, but not only do I not buy cake flour as it is bleached to weaken its proteins, I really don't think such a delicate flour is appropriate for this cake. Instead, I use a combination of unbleached white pastry flour and whole wheat pastry flour (both from Bob's Red Mill). Finally, I didn't have buttermilk, but I almost always have some soured raw milk in my fridge, which I frequently use in place of buttermilk. Sour milk provides the acid necessary to react with baking soda and create the gas bubbles that make baked goods rise. I have only tried this with raw milk, I don't know if pasteurized milk would work.
4 ounces bittersweet (about 75% cacao) chocolate, coarsely chopped
1 cup unbleached white pastry flour
1 cup whole wheat pastry flour
2 teaspoon aluminum-free baking soda
½ teaspoon salt
6 tablespoons cocoa powder
8 tablespoons (1 stick) butter, softened
2 cups Rapadura
2 teaspoons vanilla
3 eggs, at room temperature
½ cup buttermilk or soured raw milk, at room temperature
1 ¼ cups boiling water
Preheat oven to 350 degrees.
Butter a 9-inch cake pan and line the bottom with parchment paper. Butter the paper and dust the pan with flour or cocoa, shaking out the excess.
Put the chocolate into a heat-proof bowl. Set the bowl over a pan of simmering water (The water should not touch the bowl. Turn off the heat. Stir the chocolate from time to time until completely melted and smooth. Remove the bowl from over the pan.
Sift together cake flour, baking soda, salt and cocoa powder.
In a large bowl or a stand mixer, beat butter until creamy. Add sugar and vanilla and beat (cream) until light and fluffy. Beat eggs into mixture one at a time.
When egg are fully incorporated, stir in the melted chocolate. Add half the dry ingredients to this mixture and combine. Then stir in milk. Stir in the rest of the dry ingredients.
Gradually pour in 1 ¼ cups boiling water, mixing just until incorporated.
Pour batter into prepared pan and bake for 45 minutes or until toothpick inserted in the center comes out clean. Place the pan on a wire rack and allow cake to cool completely.
Run knife around the edge of the pan to loosen the cake. Remove the cake from the pan and peel off the parchment paper. If not using the same day, store the fully cooled cake in the pan, tightly covered.
For a sheet pan, prepared a half-sheet pan as above. Pour in batter, smooth the top and bake for about 20 minutes.
Or, bake in two 9-inch cake pans for a two-layer cake.
For 24 individual cupcakes, bake for about 30 minutes.