Chocolate Sourdough Cake Made With Freshly Milled Flour
This chocolate sourdough cake made with freshly milled flour uses sifted soft white wheat, Dutch cocoa powder, and sourdough discard or active starter for a deep, rich chocolate crumb with a tender, airy texture from folded whipped egg whites.
Servings: 1 9" Double Layered Cake
Calories: 9714kcal
Equipment
- 1 Grain Mill
- 1 Number 60 mesh sieve
- 1 Stand mixer with paddle attachment
- 1 Hand mixer
- 2 Nine inch round cake pans
- 1 Rubber Spatula
- 1 Kitchen scale
- 1 Wire Cooling Rack
- 1 Offset spatula
Ingredients
For the Cake
- 2½ cups soft white wheat flour freshly milled and sifted, 300 grams
- ¾ cup Dutch-process cocoa powder sifted, 75 grams
- 1 tablespoon espresso powder optional, 14 grams
- 1 tablespoon baking powder 14 grams
- ½ teaspoon baking soda 3 grams
- 1 teaspoon salt 6 grams
- 1¾ cups granulated sugar 350 grams
- ½ cup sour cream room temperature, 120 grams
- 6 large egg whites room temperature, 200 grams
- ¾ cup whole milk room temperature, 180 grams
- ⅔ cup vegetable oil or sunflower oil 150 grams
- 6 tablespoons salted butter softened, 85 grams
- ¼ cup sourdough discard or active sourdough starter 50 grams
- 1 tablespoon vanilla extract 13 grams
For the Chocolate Buttercream Frosting
- 1 cup salted butter softened to room temperature, 226 grams
- 8 ounces full-fat cream cheese softened, 226 grams
- ¾ cup Dutch-process cocoa powder sifted, 63 grams
- 4 cups confectioners sugar sifted, 480 grams
- 3 tablespoons heavy cream or milk at room temperature, 45 grams
- 1 tablespoon pure vanilla extract
Instructions
- Mill and sift the flour – Mill the soft white wheat berries on the finest setting and sift through a number 60 mesh sieve to remove the bran and achieve a cake-like texture. Weigh the sifted flour to exactly 300 grams, adding more milled flour as needed to reach the full amount. Set the sifted bran aside for another use.
- Preheat the oven and prepare the pans – Preheat the oven to 350°F. Grease and flour two 9-inch round cake pans, or line a muffin tin for cupcakes and place it on a baking sheet to catch any drips. Wrap the outside of the cake pans with water-soaked cake strips if using.
- Whisk the dry ingredients – In a large bowl, whisk together the sifted flour, cocoa powder, baking powder, baking soda, espresso powder, and salt until evenly combined. For an overnight ferment, hold back the baking powder, baking soda, and salt and set them aside to add the next morning.
- Cream the butter – In the bowl of a stand mixer fitted with the paddle attachment, beat the softened butter on medium-high speed for 2 to 3 minutes until light and fluffy.
- Add the sugar and aerate – Add the granulated sugar and continue beating until the mixture is pale, noticeably increased in volume, and almost white in color. This step builds the air structure that keeps the crumb light throughout the finished cake.
- Add the wet ingredients – Add the vegetable oil, sour cream, sourdough discard or active starter, and vanilla extract. Mix on medium speed until smooth and creamy. Stop mixing as soon as everything looks incorporated to avoid overworking the batter.
- Add the milk – Pour in the room temperature milk and stir just until combined. Scrape down the sides of the bowl to make sure everything is evenly incorporated before adding the dry ingredients.
- Fold in the dry ingredients – With the mixer on low, add the dry ingredients in three additions, mixing just until the batter looks smooth and uniform after each addition. Stop mixing as soon as no dry streaks remain.
- Overnight ferment option – At this point, cover the batter tightly and refrigerate overnight. The next morning, stir in the reserved baking powder, baking soda, and salt. Then proceed with whipping the egg whites and folding them into the batter before baking.
- Whip the egg whites – In a clean, dry bowl, whip the room temperature egg whites with a hand mixer until stiff peaks form. The whites should stand tall without collapsing when the beaters are lifted.
- Fold in the egg whites – Add one third of the whipped egg whites to the batter to loosen it, then gently fold in the remaining two thirds with a rubber spatula. Scoop from the bottom of the bowl and turn the batter over slowly to keep the air throughout.
- Fill the pans and bake – Divide the batter evenly between the two prepared cake pans using a kitchen scale for accuracy. Smooth the tops and bake for 25 to 30 minutes until a toothpick inserted in the center comes out clean.
- Cool the cakes – Let the cakes cool in the pans for 10 minutes, then turn them out onto a wire rack and cool completely before frosting. Do not frost warm cake as the frosting will melt and slide off the surface.
- Make the chocolate buttercream frosting – Beat the softened butter on medium-high speed for 2 to 3 minutes until light and pale. Add the cream cheese one piece at a time, beating well after each addition until smooth. In a separate bowl, sift together the cocoa powder and confectioners sugar. With the mixer on low, slowly add the cocoa and sugar blend to the butter and cream cheese mixture. Add the vanilla extract and heavy cream, then increase the speed to medium and beat for 2 to 3 minutes until the frosting is fluffy, smooth, and easy to spread. Add more cream one teaspoon at a time if needed to reach the right consistency.
- Frost and finish the cake – Place the first cooled layer on a cake stand or serving plate and spread a generous layer of frosting evenly over the top. Place the second layer on top and apply a thin crumb coat over the entire cake. Chill for 10 minutes in the freezer or 30 minutes in the refrigerator. Apply the final layer of frosting over the top and sides until smooth and even. Slice and serve.
Notes
Mill and sift before measuring – Sift the freshly milled flour through a number 60 mesh sieve before weighing to 300 grams. Sifting removes the bran and gives the cake its soft, tender crumb rather than a dense or gritty texture.
Bring all ingredients to room temperature – Cold butter, eggs, sour cream, milk, and starter do not blend smoothly and can cause the batter to look curdled. Pull everything out 30 to 60 minutes before starting.
Whip egg whites in a clean dry bowl – Any fat or moisture in the bowl prevents the egg whites from reaching stiff peaks. Use a metal or glass bowl and check by lifting the beaters — the whites should stand tall without collapsing.
Apply a crumb coat before the final frost – Spread a thin layer of frosting over the fully cooled cake and chill before applying the final coat. This seals in loose crumbs and gives the finished frosting a smooth, clean surface.
Nutrition
Serving: 1g | Calories: 9714kcal | Carbohydrates: 1165g | Protein: 128g | Fat: 554g | Saturated Fat: 262g | Polyunsaturated Fat: 103g | Monounsaturated Fat: 141g | Trans Fat: 11g | Cholesterol: 1975mg | Sodium: 5433mg | Potassium: 3750mg | Fiber: 78g | Sugar: 849g | Vitamin A: 13329IU | Vitamin C: 1mg | Calcium: 1929mg | Iron: 32mg