Sourdough Strawberry Cake

• Prepare the Strawberries: This is the most time-consuming step of the recipe, so I recommend preparing the strawberry puree a day in advance to help break up the recipe.
• Wash, hull, and puree the fresh strawberries with an immersion blender, in a food processor or blender. Cook the puree down in a large skillet over medium-low heat, stirring occasionally, until thick and jammy. This took about 25-30 minutes. You should be left with about 135g (½ cup) of strawberry reduction. Spread the reduction on a plate, cover and cool in the fridge overnight. The following day, remove the strawberry reduction from the fridge and allow it to come to room temperature. Alternatively, you could pop it in the freezer to cool down quickly, about 10 minutes or so, and continue on with the cake recipe on the same day.
• 454 grams strawberries
• Preheat the oven to 350 degrees F and line two 9-inch cake pans with butter and parchment paper.
• Dry Ingredients: In a medium mixing bowl, whisk together the cake flour, baking powder, baking soda and salt. Set to the side.
• 300 grams cake flour *see notes,8 grams baking powder,3 grams baking soda,5 grams salt
• Wet Ingredients: In a liquid measuring cup, whisk together the room-temperature milk, sourdough discard, 135g of strawberry puree, oil, vanilla extract and food coloring (optional) until smooth. Set aside.
• For the best outcome, it’s important that all of the ingredients are at room temperature.
• 30 grams oil,8 grams vanilla extract,120 grams milk,120 grams sourdough discard,1 gram red food coloring (optional)
• Baker's Note: You can use active sourdough starter instead of sourdough discard, just be sure to use the same amount in grams.
• In the bowl of a stand mixer with a paddle attachment, beat the sugar and soft room temperature butter at medium speed for about 4-5 minutes, or until white in color and fluffy. Scrape the bottom and sides of the bowl with a rubber spatula to ensure all of the ingredients are being mixed properly.
• 350 grams sugar,227 grams unsalted butter
• Next, add all the room-temperature egg whites, then beat the batter on high speed for about 2 minutes or until it becomes a very light and fluffy texture. Scrape the sides of the bowl once more.
• 170 grams egg whites
• Combine: While mixing on low, alternate between the dry ingredients and wet ingredients. First add about ⅓ of the flour mixture, followed by ½ of the strawberry/discard mixture. Stop mixing when there are just a few streaks of flour left and finished by hand with a rubber spatula.
• Long-Ferment: To long ferment, cover the just-mixed batter and place it into the fridge overnight. Then divide the batter evenly between two prepared cake pans and bake. You might need to add a few minutes to the bake time since the batter is chilled.
• Divide the cake batter evenly into the prepared cake pans, about 700 grams per cake pan.
• Bake: Bake the Sourdough Strawberry Cake for 20-25 minutes. The cake is done when a toothpick comes out mostly clean with a few moist bites of cake.
• Remove the cake from the oven and place on a wire rack to cool completely.

Strawberry Cream Cheese Frosting

• To a blender or food processor, process the freeze-dried strawberries until they become a fine powder. Set to the side.
• 28 grams freeze-dried strawberries
• In a stand mixer with a paddle attachment, beat the room-temperature cream cheese, for about 1 minute on high until creamy, then add the butter and continue to beat at medium speed for 2-3 minutes.
• 226 grams cream cheese, softened,113 grams unsalted butter, softened
• Next, add the powdered sugar to the butter, one cup at a time at medium speed.
• 650 grams powdered sugar
• Finally, add the freeze-dried strawberry powder, strawberry preserves, vanilla extract, and a pinch of salt. Mix until combined.
• 90 grams strawberry preserves,4 grams vanilla extract,pinch of salt
• Assemble, decorate and enjoy!

Ingredients & Substitutions

• Strawberry reduction: Strawberry reduction is what makes this cake stand out. If you just toss in chopped strawberries, you end up with a white cake with fruit bits. And adding straight strawberry puree makes the batter too runny. The fix is cooking down the puree until thick and jammy. That’s how you pack real strawberry flavor into every bite.
• Flour: For the lightest and most tender sourdough cake, I highly recommend using cake flour. This flour is lower in gluten content, which creates a lighter and fluffier bake. However, you can substitute with all-purpose flour, though this can lead to a slightly denser cake.
• Unsalted butter: For the best cake texture, the temperature of your butter is important. Before creaming, the butter should be soft enough that a fingerprint can easily be left when you press into it. If the butter is too hard or too soft, it will affect the cake’s texture. Aim for 67°F. If using salted butter, subtract 2 grams (1/2 teaspoon) of salt from the recipe.
• Leaveners: Make sure your baking powder and soda haven’t expired; otherwise, the cake won’t rise properly. Refresh these levening agents after 6 months of opening.
• Eggs: It’s important that all your ingredients are at room temperature. Bring eggs to room temperature quickly by placing them in a bowl of hot water for at least 5 minutes. I like to crack the eggs in a separate bowl first to ensure no egg shells sneak into the batter. Using only egg whites keeps the cake lighter in color, soft and fluffy. If you prefer to use whole eggs, add 3 eggs instead of 5 egg whites and skip the oil.
• Milk: I recommend using whole milk for this recipe. However, you can substitute with non-dairy options like almond milk. Bring the milk to room temperature quickly by heating it for 15-20 seconds in a microwave-safe bowl.
• Unfed sourdough starter: It’s best to use fresh sourdough discard that’s no older than 1-2 days for sweet recipes like this Sourdough Strawberry Cake. Alternatively, you can use active sourdough starter, just be sure to use the same amount in grams.
• Food coloring: It’s common for strawberries to bake up gray instead of a vibrant pink. For the most beautiful color, I like to add a food coloring, like this! You could also add a drop or two of gel food coloring or skip all together.

Vanilla Buttercream

• Freeze-dried strawberries: Not only do freeze-dried strawberries bring the delicious strawberry flavor to the frosting, but also add color. Blitz them in a food processor or blender until fine. They are different from “dried” strawberries, as these are more like raisins, while freeze-dried strawberries have all their water removed from the sliced strawberries.
• Unsalted butter: Again, in order for the frosting to be smooth, it is important that the butter is at room temperature before mixing.
• Cream cheese: Use full-fat cream cheese, not the spreadable kind sold in tubs. It’s also important that the cream cheese is softened, otherwise it will be challenging to mix evenly.
• Strawberry preserves: For one extra punch of strawberry flavor, I love adding some strawberry preserves into the frosting to add some texture. If you prefer, you can use strawberry jam instead or substitute it with heavy cream or milk for a smoother strawberry cream cheese frosting.

Alternative Baking Suggestions

Sourdough Strawberry Cupcakes

• If you want cupcakes instead, this cake batter works great for that, too. Line a muffin tin with paper liners, fill each one about three-quarters full, and bake at 350°F for around eighteen to twenty minutes.
• Use a toothpick to check if they are done. If it comes out clean, your cupcakes are ready. Let them cool completely before frosting. Top with the strawberry cream cheese frosting and add a fresh strawberry on top if you want to.

Sourdough Strawberry Sheet Cake

• If you’re not into stacking cake layers, make a sheet cake. Pour the batter into a greased 9 by 13-inch pan and bake it at 350°F for about 30 to 35 minutes. Let it cool before frosting. This version is easy to slice and serve for a casual get-together or just a regular day at home.
• If you want to make smaller cakes or go with a sheet-style bake, this batter works nicely for that too. You can use six-inch pans or spread it into thinner layers. Just check a little earlier, as thinner cakes bake a little faster.