Ingredients
Dry Ingredients
- 300 grams cake flour
- 1 ¼ teaspoons baking powder
- ¼ teaspoon baking soda
- ¼ teaspoon fine sea salt
- 1 teaspoon vanilla powder
- 350 grams granulated sugar (divided)
Wet Ingredients
- 250 ml milk (room temperature)
- 1 teaspoon apple cider vinegar
- 3 large eggs (separated, room temperature)
- 3 egg yolks
- 150 grams salted butter (melted and cooled to room temperature)
- 100 grams sourdough starter
- 2 tablespoons oil (avocado or vegetable)
- 2 teaspoons vanilla extract
Instructions
- Prepare the pans: Preheat the oven to 350°F (180°C). Grease and line two 9-inch (23cm) cake pans with parchment paper, then grease the parchment again with butter. Set aside.
- Mix dry ingredients: In a large mixing bowl, whisk together cake flour, baking powder, baking soda, fine sea salt, vanilla powder, and 300 grams of granulated sugar until well combined. Set aside.
- Curdle the milk: Combine the room temperature milk and apple cider vinegar in a small bowl and let sit for a few minutes to curdle.
- Separate the eggs: Carefully separate the eggs into two bowls: place three egg whites in one bowl and six egg yolks in another, ensuring no yolk contaminates the whites.
- Combine wet ingredients with yolks: Add the curdled milk, cooled melted butter, sourdough starter, oil, and vanilla extract to the bowl with egg yolks. Whisk until fully incorporated and set aside.
- Beat egg whites: Add 50 grams of sugar to the egg whites. Using electric beaters or a standing mixer with a whisk attachment, beat the egg whites on low until foamy, increase to medium speed until peaks begin to form, then continue beating until stiff, glossy peaks form, about 3 minutes more.
- Combine wet and dry mixtures: Pour the egg yolk mixture into the dry ingredients and whisk gently just until combined without overmixing.
- Fold in egg whites: Add one-third of the beaten egg whites to the batter, stir gently with a spatula to incorporate. Add the remaining egg whites and fold carefully to maintain airiness, ensuring no visible streaks remain and the batter is light and fluffy.
- Divide and smooth batter: Divide the batter evenly between the two prepared cake pans and smooth the tops with a spatula.
- Bake: Place the pans on the middle oven rack and bake for 20 to 22 minutes. Test doneness by inserting a wooden skewer or toothpick into the center; it should come out clean.
- Cool the cakes: Remove from oven and cool the cakes on a wire rack for 15 minutes. Carefully remove from the pans and parchment, then cool completely on the rack, covering lightly with a cotton or linen tea towel to prevent drying.
- Frost the cake: Once fully cooled, frost with chocolate buttercream or your preferred icing. The given amount of chocolate buttercream is suitable for this two-layer cake.
Notes
- Use room temperature ingredients (eggs, milk, butter) for best mixing and texture.
- Vanilla powder can be substituted with an equal amount of pure vanilla extract if unavailable.
- Be cautious when folding in egg whites to retain volume and create a light cake.
- Covering the cake layers with a cloth while cooling prevents them from drying out.
- Sourdough starter adds a subtle tang and depth of flavor not found in traditional vanilla cakes.
- Prep Time: 20 minutes
- Cook Time: 22 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
