Lesson 11: Sourdough Cocoa Cake

This cake is a good example of the way you can add sourdough to everyday baked goods to impart moistness and to enhance them in an almost indescribable way. The recipe calls for resting the sourdough mixture for 1 hour or, if you have time, for 12 hours; this longer rest can lower the glycemic effect of the cake (that is, limit its impact on blood sugar) and improve its healthfulness, just as a rest does for sourdough bread. The flavor and texture, however, will be the same no matter which rest you choose. Serve this cake alone or with lightly whipped cream and fresh berries.

Makes one 9” cake


½ cup (3.5 ounces) sourdough starter
1 cup (5 ounces) all-purpose flour
¾ cup plus 2 tablespoons (4.5 ounces) whole-wheat pastry flour
2/3 cup (6 ounces) whole milk
olive oil to coat the pan
¾ cups (2.6 ounces) unsweetened cocoa powder (not Dutch process)
½ teaspoon fine sea salt
1 teaspoon baking powder
¼ teaspoon baking soda
1/3 cup (2.6 ounces) water
1 tablespoon plus ½ cup (3.9 ounces) extra-virgin olive oil
1-3/4 cups (11 ounces) maple crystals
4 eggs
1 teaspoon vanilla


  1. In a medium bowl, mix the sourdough starter, flours, and milk until they are well combined. Use your hands to break up any lumps in the dough-like batter and knead for a moment to finish combining the ingredients; the batter may be sticky. Cover the batter and transfer it to the refrigerator to rest for 12 hours (in this case, incorporate time within the 12-hour rest to bring the batter to room temperature before moving on to step 2). Alternatively, rest the batter at room temperature for 1 hour and then move on to step 2.
  2. About 15 minutes before the end of your chosen rest period, preheat oven to 350 degrees. Line the bottom of a 9” round cake pan with parchment paper, and use 1 tablespoon of olive oil to coat both the bottom and sides of the pan.
  3. In a small bowl, whisk together the cocoa powder, sea salt, baking powder and baking soda and set aside
  4. Uncover the sourdough mixture and add the water. Using your hands, begin working the water into the batter and breaking up any clumps of dough (you will not be able to fully incorporate the water). Press and knead until you have a thoroughly wet mass and then set aside.
  5. In a large mixing bowl or the bowl of a stand mixer, combine the olive oil and maple crystals and mix on a medium speed until the crystals are coated with oil and have a sandy, granular appearance, about 1-2 minutes. Turn the speed to low, add the cocoa powder mixture, increase the speed back to medium, and mix for 1-2 minutes more or until the granules are evenly coated with cocoa and the mixture resembles chocolate cookie crumbs. With the mixer still on medium, add the eggs one at a time. With the last egg incorporated, turn the mixer to medium-high and beat for 2-3 minutes, scraping the sides and bottom once, until the mixture resembles chocolate pudding. Add the vanilla and mix a moment longer.
  6. Adjust the speed to low, add half the sourdough mixture and mix just to combine. Then add the second half and mix for 1 minute more, scraping the beaters with a spatula to release any sourdough clumps.
  7. Finish mixing with an immersion blender; I have so far found this to be the most effective way to break up the sourdough clumps and integrate them into the batter.  Mix and stir with the immersion blender for 1 minute. Scrape the sides and bottom of the bowl with a rubber spatula. Then mix and stir with the immersion blender for 1-1/2 minutes more. In the end, the batter should be smooth and uniformly brown.
  8. Pour the batter into the prepared cake pan, using a spatula to scrape the batter off the sides and bottom of the bowl.
  9. Bake the cake for 55 minutes, or until a toothpick or cake tester comes out clean. Cool the cake in the pan for 20 minutes; then slide a thin knife around the edge of the cake and invert it onto a plate. Turn the cake right side up onto a cooling rack and serve it lukewarm or at room temperature. Lightly whipped cream and fresh berries make a nice addition.


  • The trick with this cake, if there is one, is to smooth any clumps of sourdough in the mixture and integrate them into the batter without overworking it. Too much mixing and handling develops gluten, which is not our aim. With a cake, the goal is “tender,” not “chewy.” So while it’s important to be sure there are no sourdough clumps left in the finished cake, you also want to avoid over-mixing it, which would toughen the light texture. Practice will be your best guide.
  • I made this cake dozens of different ways before settling on olive oil for the moisture it imparts. When choosing an olive oil, look for one labeled “mellow,” “smooth,” or “buttery.” Avoid oils labeled “peppery” or “pungent.” Better yet, taste a spoonful of olive oil and decide for yourself.

Next Up: Sourdough Banana Bread

Copyright 2014, Ellen Arian, Ellen’s Food & Soul