Sourdough Blueberry Crumb Cake

A Sourdough Blueberry Crumb Cake is a moist, fluffy cake made using sourdough discard, giving it a subtle tang and enhanced texture. It’s filled with juicy blueberries and topped with a buttery cinnamon crumble, offering layers of texture and flavor in every bite. Perfect for breakfast, brunch, or dessert, this cake highlights the utility of sourdough discard and makes your kitchen smell amazing.

Sourdough discard is the portion of starter you’d normally toss during feeding. But in this recipe, it plays a hero role—adding depth and richness that takes the classic crumb cake to new heights.

Why You’ll Love This Recipe

• ✅ Great Use of Sourdough Discard – No waste, just taste!
• 💜 Fresh Blueberries – Bursts of fruity flavor in every bite.
• 👩‍🍳 Simple to Make – Easy ingredients and steps anyone can follow.
• 🍰 Moist and Buttery – The sour cream and butter combo is unbeatable.
• 🌾 Crunchy Crumb Topping – Adds a delightful texture contrast.
• 🍽️ Perfect for Any Occasion – Breakfast, snack, or dessert? Yes to all!

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What you will need?

Let’s break it down:

Cake Ingredients:

• 🧈 8 tbsp (113g) salted butter
• 🍚 1 cup (200g) sugar
• 🥚 1 large egg
• 🍞 1/2 cup (120g) sourdough starter discard
• 🌾 2 cups (240g) all-purpose flour
• 🥄 1 tsp baking powder
• 🥄 1/2 tsp baking soda
• 🧂 1/4 tsp sea salt
• 🍶 1/2 cup (120g) sour cream

For the Blueberries:

• 💜 1 heaping cup fresh blueberries
• 🍚 Powdered sugar, plus more for serving

Crumble Topping:

• 🍬 1/4 cup (50g) sugar
• 🍯 1/2 cup (100g) light brown sugar
• 🌾 1 1/2 cups (180g) all-purpose flour, spooned and leveled
• 🍂 1/2 tsp cinnamon (or 1 tsp for extra flavor)
• 🧂 Pinch of sea salt
• 🧈 8 tbsp (113g) salted butter, cut into small cubes, cold

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How to Make Sourdough Blueberry Crumb Cake

Follow these easy steps for a foolproof cake:

Step 1: Prepare the Crumble Topping

In a Mixing bowl, combine sugar, brown sugar, flour, cinnamon, sea salt, and cold butter cubes. Use your hands or a pastry cutter to blend until crumbly. Place in the fridge while preparing the batter.

Step 2: Make the Cake Batter

Cream together butter and sugar until fluffy. Add the egg and mix well. Stir in sourdough discard and sour cream until smooth. In another bowl, whisk together flour, baking powder, baking soda, and salt. Gradually add to wet mixture and mix until just combined.

Step 3: Fold in the Blueberries

Gently fold in the fresh blueberries. Avoid overmixing to prevent them from breaking and bleeding into the batter.

Step 4: Assemble and Bake

Preheat oven to 350°F (175°C). Grease an 8×8-inch baking pan. Pour the batter into the pan and spread evenly. Sprinkle the crumble topping generously over the top. Bake for 40-45 minutes or until a toothpick inserted in the center comes out clean.

Step 5: Cool and Dust

Let the cake cool before dusting with powdered sugar. Slice and serve warm or at room temperature.

Tips for Perfect Results

To ensure your Sourdough Blueberry Crumb Cake turns out flawless every time, here are a few pro tips:

Use Room Temperature Ingredients

Butter, eggs, and sour cream mix better when they’re not cold. This ensures a smoother batter and even baking.

Don’t Overmix the Batter

Once you add the flour mixture, mix just until combined. Overmixing can lead to a dense cake.

Cold Butter for the Crumble

Use very cold butter when making the crumble topping. This creates that classic crispy, crumbly texture.

Fresh Over Frozen

Fresh blueberries yield the best results. If using frozen, don’t thaw them first—toss in a bit of flour to prevent them from bleeding into the batter.

Let it Cool Before Cutting

As tempting as it is to slice into it warm, allowing it to cool helps the cake set and makes for cleaner slices.

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Substitutions & Variations

Don’t have everything on hand? No worries—here are some handy swaps and twists:

Ingredient Substitutions:

• Sour Cream: Swap with Greek yogurt or plain yogurt.
• Sourdough Discard: Use plain yogurt or buttermilk if discard isn’t available (you’ll miss the flavor complexity, though).
• Butter: Unsalted butter works; just add a pinch more salt to the recipe.
• Brown Sugar: Use coconut sugar for a healthier twist.

Flavor Variations:

• Lemon Blueberry: Add lemon zest and a teaspoon of lemon juice to the batter.
• Spiced Crumble: Add nutmeg or cardamom to the topping for extra depth.
• Nutty Crumb: Add 1/4 cup chopped walnuts or pecans to the crumble for crunch.

Other Fruit Options:

1. Raspberries
2. Chopped strawberries
3. Blackberries
4. Cherries (pitted and halved)

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Storage & Freezing

This cake keeps well and freezes beautifully, making it perfect for prep ahead!

How to Store:

• Room Temp: Store in an airtight container for up to 2 days.
• Fridge: Keeps for 5–6 days in an airtight container.

Freezing Instructions:

1. Let the cake cool completely.
2. Wrap individual slices tightly in plastic wrap and place in a freezer-safe container.
3. Freeze for up to 3 months.
4. Thaw at room temperature or warm in the microwave for 20-30 seconds.

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Serving Suggestions

Pair your Sourdough Blueberry Crumb Cake with:

• A scoop of vanilla ice cream 🍨
• A dollop of whipped cream 🍦
• A drizzle of lemon glaze 🍋
• Fresh berries on the side 🍓
• Hot coffee or iced tea ☕🧊

Perfect for brunch tables, afternoon tea, or a sweet morning treat!

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FAQs

Whether you’re a seasoned sourdough baker or just looking for a way to reduce food waste, this Sourdough Blueberry Crumb Cake is a must-try. With its tangy, moist base, sweet blueberries, and a buttery cinnamon crumble, it checks every box for comfort food done right.

So grab your apron, preheat that oven, and treat yourself (and your loved ones) to a slice of this delightful cake. Your kitchen will smell amazing, and your taste buds will thank you.