Sourdough Vanilla Cake with Cream Cheese Frosting

Introduction

You can transform your tangy sourdough discard into a delightfully moist and tender vanilla cake. The subtle complexity from the discard pairs perfectly with classic cream cheese frosting for a dessert that feels both special and comforting. This recipe is a fantastic way to use up your discard without any extra work.

This recipe and accompanying image were created with the help of AI for inspiration and guidance. Results may vary depending on ingredients, equipment, and technique.

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

Preheat your oven to 350°F (175°C). Grease and flour two 8-inch round cake pans, or line them with parchment paper.
In a large bowl, whisk together the cake flour, baking powder, and the first 1/4 teaspoon of salt. Set aside.
In a separate bowl, whisk together the granulated sugar, 8 tablespoons of melted butter, and the 3 egg whites until smooth and slightly thickened.
Whisk the 2 teaspoons of vanilla extract, the whole milk, and the sourdough discard into the sugar-butter mixture until fully incorporated.
Divide the batter evenly between the prepared cake pans. Bake for 38-42 minutes, or until a toothpick inserted into the center comes out clean.
Let the cakes cool in their pans for 10 minutes, then carefully turn them out onto a wire rack to cool completely before frosting.
For the Frosting: While the cakes cool, make the frosting. In a large bowl, beat the softened cream cheese and the softened 1 cup (2 sticks) of salted butter with an electric mixer on medium-high speed until very smooth and creamy, about 2-3 minutes.
Beat in the 2 teaspoons of vanilla extract and the 1/8 teaspoon of salt.
With the mixer on low speed, gradually add the sifted powdered sugar. Once incorporated, increase the speed to high and beat for 1-2 minutes until the frosting is light and fluffy.
Once the cake layers are completely cool, frost as desired, placing one layer on a plate or cake stand, spreading frosting on top, adding the second layer, and frosting the top and sides.

Variations

Cupcakes: Divide the batter into lined muffin tins and bake for 18-22 minutes. This recipe makes approximately 18-20 cupcakes.
Layered Dessert: Crumble one cake layer into a trifle dish with layers of frosting and fresh berries.
Flavor Twist: Add the zest of one lemon or orange to the cake batter and frosting for a citrus twist.
Naked Cake: For a rustic look, apply a very thin “crumb coat” of frosting to the assembled cake and scrape most of it off, leaving the cake layers slightly visible.

Tips for Success

Ensure all your refrigerated ingredients (discard, milk, eggs, cream cheese, butter) are truly at room temperature for a smooth, even batter and lump-free frosting.
To make your own cake flour, simply whisk together 1 3/4 cups + 2 tablespoons of all-purpose flour with 1/4 cup of cornstarch, then measure out 2 cups for the recipe.
For the smoothest frosting, sift your powdered sugar. This prevents lumps and creates a silky texture.

Storage & Reheating

Store any leftover cake, covered, in the refrigerator for up to 5 days due to the cream cheese frosting. The unfrosted cake layers can be wrapped tightly in plastic wrap and frozen for up to 3 months. Thaw at room temperature before frosting. This cake is best served at room temperature.

FAQ

Can I use active sourdough starter instead of discard?

Yes, you can use unfed, ripe starter (discard) or active starter. The result will be very similar, as the baking powder provides the primary leavening.

My discard is very thick. Is that okay?

Yes, thickness can vary. As long as it’s at room temperature and you can stir it into the batter smoothly, it will work fine.

Why use only egg whites?

Using only egg whites creates a lighter, more tender crumb with a bright white color that pairs beautifully with vanilla flavor.

Can I use unsalted butter?

Yes, you can use unsalted butter. For the cake, simply proceed as directed. For the frosting, you may want to increase the salt very slightly to balance the sweetness.

My frosting is too soft. How can I fix it?

If your frosting is too soft to spread, the butter or cream cheese may have been too warm. Chill the mixing bowl in the refrigerator for 15-20 minutes, then beat again. You can also add a little more sifted powdered sugar, a quarter cup at a time.

Can I make this cake ahead of time?

Absolutely. You can bake and cool the cake layers a day ahead. Wrap them tightly in plastic wrap and store at room temperature. Make the frosting and assemble the cake the day you plan to serve it.