Blueberry Sourdough Cake – Simple Cozy Dessert

Recent Recipes

This BLUEBERRY SOURDOUGH CAKE is the perfect way to use up your sourdough discard while treating yourself to a moist, flavorful dessert. Bursting with juicy blueberries and a hint of tangy sourdough, it’s easy to make and even easier to love. Whether you’re enjoying it with a cup of coffee or sharing it with friends, this cake is a delightful twist on a classic favorite!

When we first started our sourdough journey, it was all about the bread. But as we nurtured our starter and fed it regularly, we quickly realized we needed more ways to use up the discard. That’s how this Blueberry Sourdough Cake came to life. It’s a delicious and unexpected way to put your sourdough starter to work, and honestly, it’s become one of our favorite treats to make.

This cake strikes the perfect balance between indulgent and comforting. The sourdough discard gives it a subtle tang that enhances the sweetness of the blueberries, while the soft, fluffy texture makes every bite irresistible. Whether you’re using fresh or frozen blueberries, this cake comes out bursting with juicy flavor, and the light sprinkle of sugar on top creates a golden, slightly crisp finish that feels extra special.

If you’ve ever found yourself wondering what else you can do with sourdough starter besides baking bread, this recipe is the answer. It’s a creative way to make the most of that discard while treating yourself to something truly delicious. Trust me, once you try it, this Blueberry Sourdough Cake will become a go-to in your baking repertoire!

What do I need to make this cake?

ALL-PURPOSE FLOUR & CORNSTARCH: The cornstarch lightens the flour mixture, giving the cake a delicate crumb that complements the juicy blueberries. Be sure to toss the blueberries in a bit of flour before folding them into the batter—this simple trick keeps them evenly distributed throughout the cake instead of sinking to the bottom.

SOURDOUGH DISCARD OR FRESH STARTER: The sourdough discard is what makes this cake truly special. Discard is the portion of starter that’s removed before feeding to maintain the right balance in your starter. Its subtle tang enhances the sweetness of the cake, giving it a unique flavor you can’t get with traditional ingredients.
If you’ve just fed your starter and have some discard on hand, this is the perfect way to use it up. However, you can also use fresh, active sourdough starter for this recipe, much like you would in a loaf of bread. Active starter will lend a slightly stronger tang and may even give the cake a bit more lift due to the active yeast. Just keep in mind that whether you’re using discard or fresh starter, the measurement remains the same—it’s a flexible recipe that works beautifully with either option.
BUTTER, SUGAR, & EGGS: Be sure to cream the butter and sugar together thoroughly—this step aerates the batter, giving the cake its light, tender texture. The eggs act as a binder and help the cake rise, ensuring it stays moist and fluffy.
BLUEBERRIES: The stars of this recipe, blueberries bring bursts of juicy sweetness to every bite. You can use either fresh or frozen blueberries, depending on what you have on hand. Frozen blueberries work just as well, but be sure not to thaw them before tossing them in flour—this helps prevent excess liquid from affecting the batter.
BAKING POWDER & BAKING SODA: The combination of baking powder and baking soda gives the cake the perfect rise. The baking soda works with the acidity in the sourdough discard to create lift, while the baking powder ensures the cake rises evenly.
VANILLA EXTRACT & MILK: The whole milk keeps the batter smooth and moist and balance the tanginess of the sourdough.
SUGAR TOPPING: A sprinkle of granulated sugar on top before baking adds a touch of sweetness and creates a golden, slightly crunchy crust that contrasts beautifully with the soft, fluffy cake. It’s a simple step that makes the cake feel extra special and bakery-worthy.

Can I make this if I don’t have sourdough starter?

Of course–it’s easy to adapt the recipe! To replace the ¾ cup (170 grams) of sourdough starter in the recipe, use the following mixture as a substitute:

⅓ CUP (45 GRAMS) ALL-PURPOSE FLOUR: This provides the same structure and thickness that the flour in the starter contributes.
⅓ CUP (80 GRAMS) BUTTERMILK, YOGURT, OR MILK: These liquids add moisture to the batter while also introducing a slight tanginess to replicate the sour flavor of the starter. Buttermilk is ideal, but plain yogurt or even regular milk with a teaspoon of lemon juice or vinegar stirred in can work well too.
1 TEASPOON OF LEMON JUICE OR VINEGAR (IF USING PLAIN MILK): Adding a small amount of acidity ensures you still get that subtle tang that makes the cake so unique.

Simply combine these ingredients, mix well, and use the mixture in place of the sourdough starter in the recipe. The batter consistency should remain the same, and the flavor will still have a slight tang reminiscent of the original.

Step-by-Step Instructions

1. Preheat the Oven & Prepare Your Baking Dish

Start by preheating your oven to 350°F (175°C). While the oven heats, prepare a 9×9-inch baking dish by lining it with parchment paper. To make sure the paper sticks and doesn’t move around, lightly spray or grease the pan first, then press the parchment into place. Finally, spray the parchment with cooking spray to prevent the cake from sticking. This step is key to easy removal later.

2. Mix the Dry Ingredients

In a medium mixing bowl, whisk together the flour, cornstarch, baking soda, baking powder, and salt. Using a whisk also helps aerate the dry ingredients, resulting in a fluffier cake.

3. Cream the Butter & Sugar

In the bowl of a stand mixer fitted with the paddle attachment, cream the softened butter and sugar on medium-low speed for about 5 minutes. The mixture should become light and fluffy. This step is crucial for incorporating air into the batter, which helps create the cake’s tender texture. Scrape down the sides of the bowl periodically to ensure everything is evenly mixed.

4. Add the Eggs

With the mixer running on low, add the eggs one at a time, making sure each egg is fully incorporated before adding the next. This gradual mixing prevents the batter from curdling and ensures a smooth texture. If your batter looks slightly lumpy at this stage, don’t worry—it will come together once the dry ingredients are added.

5. Incorporate the Wet Ingredients

Add the milk, sourdough discard, and vanilla extract to the batter. Mix on low speed just until everything is combined. The sourdough discard brings a subtle tang to the cake, enhancing the flavor while keeping it moist. Make sure not to overmix, as you want to avoid activating the gluten in the flour too much, which can result in a denser cake.

6. Add the Dry Ingredients

With the mixer on low, gradually add the dry ingredients, one large spoonful at a time. Let each addition mix in slightly before adding more. If there are any small streaks of flour left at this point, don’t worry—you’ll fold them in when you add the blueberries.

7. Fold in the Blueberries

In the bowl where you mixed your dry ingredients, toss the blueberries with ⅓ cup of flour until they’re evenly coated. This step helps keep the blueberries suspended in the batter instead of sinking to the bottom. Add the floured blueberries to the batter and gently fold them in using a spatula, along with any remaining dry flour in the bowl. Be careful not to crush the berries as you fold.

8. Pour & Top the Batter

Pour the batter into your prepared baking dish, spreading it out evenly. For a beautiful finish, sprinkle about 2 tablespoons of granulated sugar over the top. This creates a golden, slightly crunchy crust that complements the cake’s soft interior.

9. Bake & Test for Doneness

Place the dish in the preheated oven and bake for 45-50 minutes, or until the top is golden brown. To test for doneness, insert a toothpick or cake tester into the center of the cake. If it comes out clean or with just a few crumbs, the cake is ready. If you notice wet batter on the tester, give it another 5 minutes and check again.

10. Cool & Serve!

Once baked, allow the cake to cool in the pan for about 15 minutes. Then, lift it out using the parchment paper and transfer it to a wire rack to cool completely. Serve warm or at room temperature with a sprinkle of powdered sugar or a dollop of whipped cream for an extra touch.

Common Mistakes & How to Avoid Them

BLUEBERRIES SINKING: If you skip tossing the blueberries in flour, they’re likely to sink to the bottom during baking. The flour coating helps them stay evenly distributed throughout the cake.
OVERMIXING THE BATTER: Mixing too much after adding the dry ingredients can lead to a dense, tough cake. Once the dry ingredients are mostly combined, switch to folding in the blueberries by hand to avoid overworking the batter.
BUTTER NOT SOFTENED ENOUGH: If your butter is too cold, it won’t cream properly with the sugar, and your cake may turn out dense. Make sure your butter is softened at room temperature—it should be pliable but not melted.
UNDERBAKING: Pulling the cake out too early can leave you with a wet center. Use a toothpick or cake tester to ensure the middle is fully baked before removing it from the oven.
SKIPPING THE SUGAR TOPPING: While optional, the sugar topping creates a beautiful crust that adds texture and sweetness. Don’t skip this step—it elevates the cake to bakery-level perfection!