Sourdough Vanilla Cake with Cream Cheese Frosting

Introduction

This recipe transforms your everyday sourdough discard into an exceptionally tender and flavorful vanilla cake. The natural acidity from the discard creates a delicate crumb and enhances the overall vanilla taste, perfectly balanced by a rich, tangy cream cheese frosting. You’ll love how it turns a “waste” ingredient into the star of a sophisticated dessert.

Prep & Cook Time

Prep Time: 10 minutes

Cook Time: 42 minutes

Total Time: 52 minutes

Servings: 8

Ingredients

• 2 cups cake flour (or 2 cups all-purpose flour minus 4 tbsp, replaced with 4 tbsp cornstarch)
• 2 tablespoons baking powder
• 1/4 teaspoon salt
• 1 1/2 cups granulated sugar
• 8 tablespoons melted butter (salted butter)
• 3 egg whites
• 2 teaspoons vanilla extract
• 3/4 cup whole milk (room temperature)
• 1 cup sourdough discard (room temperature)
• 8 ounces cream cheese (softened)
• 1 cup 2 sticks salted butter (softened)
• 2 teaspoons vanilla extract
• 1/8 teaspoon salt
• 4 cups powdered sugar (sifted)

Instructions

For the Cake:

1. Preheat your oven to 350°F (175°C). Grease and line two 8-inch round cake pans or one 9×13-inch baking pan with parchment paper.
2. In a medium bowl, whisk together the cake flour, baking powder, and 1/4 teaspoon salt. Set aside.
3. In a large mixing bowl, combine the granulated sugar, melted butter, egg whites, and 2 teaspoons vanilla extract. Whisk vigorously until smooth and slightly glossy.
4. Add the milk and sourdough discard to the wet ingredients, whisking until fully incorporated.
5. Divide the batter evenly between the prepared pans. Bake for 40-42 minutes, or until a toothpick inserted into the center comes out clean.
6. Let the cakes cool in their pans for 10 minutes before turning them out onto a wire rack to cool completely.

For the Frosting:

1. While the cakes cool, prepare the frosting. In a large bowl, beat the softened cream cheese and 1 cup (2 sticks) softened butter together on medium speed until perfectly smooth and creamy, about 2-3 minutes.
2. Beat in the 2 teaspoons vanilla extract and the 1/8 teaspoon salt.
3. Gradually add the sifted powdered sugar, about one cup at a time, beating on low speed until combined after each addition. Once all sugar is incorporated, beat on medium-high speed for 1-2 minutes until the frosting is light and fluffy.
4. Once the cakes are completely cool, frost as desired. For a layer cake, spread frosting between the layers and over the top and sides. For a 9×13-inch sheet cake, spread frosting evenly over the top.

Variations

• Loaf Cake: Bake the batter in a greased 9×5-inch loaf pan for about 50-60 minutes. A simple vanilla glaze can replace the frosting for a less decadent treat.
• Cupcakes: Divide the batter into lined muffin tins, filling each cup 2/3 full. Bake for 18-22 minutes. This recipe makes about 18-20 cupcakes.
• Berry Compote Filling: Add a burst of fruit flavor by spreading a thin layer of homemade berry compote between the cake layers before frosting.
• Cinnamon Swirl: Before baking, sprinkle a mixture of cinnamon and sugar over the batter in the pan and gently swirl with a knife for a marbled effect.

Tips for Success

• Room Temperature is Key: Ensure your milk, sourdough discard, cream cheese, and butter for the frosting are all at room temperature. This prevents a lumpy frosting and ensures even mixing for a smooth cake batter.
• Cool Cakes Completely: Never frost a warm cake. The frosting will melt and slide right off. Allow the cakes to cool completely on a wire rack, which can take 1-2 hours.
• Sift the Sugar: Sifting the powdered sugar for the frosting is non-negotiable. It removes any lumps and incorporates air, resulting in a silky-smooth frosting.

Storage & Reheating

Store the frosted cake, covered, in the refrigerator for up to 5 days. The unfrosted cake layers can be wrapped tightly in plastic wrap and frozen for up to 3 months. Thaw overnight in the refrigerator before frosting. For the best texture, let slices sit at room temperature for 20-30 minutes before serving.

FAQ

Can I use active sourdough starter instead of discard?

Yes, you can use unfed, active starter, but the discard’s acidity is what benefits the cake’s texture. Just ensure it’s at room temperature.

My cake is very dense. What happened?

This is likely from overmixing the batter after adding the dry ingredients. Gently fold just until combined. Also, check that your baking powder is fresh.

Can I use whole eggs instead of just egg whites?

Yes, but the cake will be slightly less light and tender and may have a subtle yellow tint. The egg yolks add richness but also fat and density.

Why is my frosting runny?

Your cream cheese or butter was likely too warm, or the cake wasn’t fully cooled. Chill the frosting bowl for 20 minutes and re-beat. Always use full-fat, brick-style cream cheese.

What if I don’t have cake flour?

Use the provided substitution exactly: measure 2 cups of all-purpose flour, then remove 4 tablespoons of it and replace with 4 tablespoons of cornstarch. Whisk thoroughly.

Can I use unsalted butter?

Yes. If using unsalted butter for the cake, you may want to increase the 1/4 teaspoon salt to 1/2 teaspoon. For the frosting, you can keep the 1/8 teaspoon salt as is.