My sourdough lemon snack cake is soft, buttery, and full of bright, fresh lemon flavor. The sourdough discard adds a subtle tang that balances the sweetness, while the lemon buttercream makes it feel extra special and indulgent — all in one easy 8x8 pan with no layering or decorating stress.
If you love a good lemon dessert, you'll also want to try my lemon blueberry mascarpone cake and my lemon blackberry layer cake. And for something just as spring-perfect but more like a pie, my strawberry rhubarb galette is a forever favorite.
Quick Look: Sourdough Discard Lemon Snack Cake
⏱️ Ready In: About 1 hour 15 minutes
🔥 Bake Time: 30–35 minutes at 350°F
🍽️ Makes: 9 squares
✨ Calories: Approximately 495 per serving
🥄 Main Ingredients: Lemon (zest + juice), sourdough discard, butter, sour cream, lemon buttercream
🌿 Dietary Info: Vegetarian
💛 Why You'll Love It: A bright, tender lemon cake with creamy lemon buttercream — bakery-style flavor with zero layer-cake fuss.
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Why You’ll Love This Recipe
- A perfect use for sourdough discard. It adds depth and a subtle tang that makes the lemon pop.
- Soft, tender crumb. Butter and oil together keep it moist for days.
- Bright lemon flavor. From both zest and juice, the same citrus-forward approach as my sourdough lemon pound cake.
- Creamy lemon buttercream. A bakery-style finish that balances the tangy cake.
- No layer-cake stress. A simple 8x8 snack cake — no stacking, no crumb coat, no decorating.
Jump to:
- Quick Look: Sourdough Discard Lemon Snack Cake
- Why You’ll Love This Recipe
- Ingredients
- Easy Substitutions & Variations
- How to Make Sourdough Lemon Snack Cake
- Expert Tips
- What Makes This Recipe Special?
- Sourdough Lemon Snack Cake FAQs
- Sourdough Lemon Snack Cake Troubleshooting Guide
- Storage
- Other Cake Recipes to Consider
- Sourdough Discard Lemon Snack Cake
Ingredients
For the cake
- All-purpose flour: The structure of the cake.
- Granulated sugar: Sweetens, and carries the lemon oils when you rub in the zest.
- Baking powder + baking soda: Your lift for a soft, even crumb.
- Fine sea salt: Balances the sweetness.
- Lemon zest: Where most of the lemon flavor lives — rub it into the sugar to release the oils.
- Unsalted butter + neutral oil: Butter for flavor, oil to keep the cake moist even after chilling.
- Eggs: Bind and enrich the batter.
- Sourdough discard: Unfed discard adds moisture and a subtle tang.
- Sour cream or Greek yogurt: Adds richness and a tender crumb.
- Fresh lemon juice: Fresh is best — bottled can taste flat, the same reason I call for fresh in my fresh lemon crumb bars.
- Vanilla extract: Rounds out the flavor.
For the lemon buttercream
- Unsalted butter, powdered sugar, fresh lemon juice, lemon zest, vanilla, and a pinch of salt: Whipped into a creamy, not-too-sweet lemon frosting.
See recipe card for quantities.
Easy Substitutions & Variations
- Want chocolate instead? When you're craving something richer, my sourdough chocolate cupcakes use the same easy discard approach.
- Sour cream: Plain Greek yogurt works beautifully for a slightly lighter texture.
- Butter: Replace with all oil for an extra-moist crumb.
- Lemon juice: Bottled works in a pinch, but fresh is best.
- Sourdough discard: Active starter can be used in place of discard.
- Lemon blueberry: Fold 120g (¾ cup) blueberries into the batter.
- Lemon poppy seed: Add 1 tablespoon poppy seeds to the batter — or try the same bright lemon flavor in muffin form with my sourdough lemon muffins.
- Lemon coconut: Add 50g (½ cup) shredded coconut for extra texture.
How to Make Sourdough Lemon Snack Cake
Note: I bake by weight for accuracy. Cup measurements are approximate and may vary depending on how you scoop.
Step 1: Make the batter: Rub the lemon zest into the sugar until fragrant. Whisk in the melted butter, oil, eggs, sourdough discard, sour cream, lemon juice, and vanilla until smooth, then fold in the dry ingredients until just combined.
Step 2: Bake: Pour into a parchment-lined 8x8 pan and bake at 350°F for 30–35 minutes, until lightly golden and a toothpick comes out clean.
SStep 3: Cool: Let the cake cool in the pan 15 minutes, then transfer to a rack and cool completely before frosting.
Step 4: Frost: Beat the lemon buttercream until fluffy, spread over the cooled cake, and slice into squares.
Weigh your ingredients! Using a kitchen scale ensures your measurements are accurate, which is key for getting consistent results in baking. It takes the guesswork out of measuring and helps your recipes turn out exactly as intended every time.
Expert Tips
- Rub the lemon zest into the sugar. This releases the natural oils and gives the cake a much stronger, brighter lemon flavor without adding extra liquid.
- Use fresh lemon juice. Bottled juice tastes flat by comparison; fresh is what makes the cake taste vibrant.
- Don't overmix. Fold the dry ingredients in just until combined for a tender crumb.
- Cool completely before frosting. Warm cake will melt the buttercream right off.
- Older discard = more tang. Discard that's 7–10 days old brings a slightly stronger flavor, which works beautifully here.
What Makes This Recipe Special?
Most lemon cakes taste like lemon extract; this one tastes like actual lemons because the zest gets bloomed in the sugar before anything else. The sourdough discard does quiet but important work too, adding moisture and a gentle tang that keeps all that sweetness in check. And because it's a single 8x8 pan with a simple buttercream, you get bakery-style flavor without any of the layer-cake effort.
It's also part of a whole family of easy, low-stress snack cakes. If you love this format, try my spiced zucchini snack cake and my sourdough discard carrot snack cake. And when you want something more indulgent, my chocolate sheet cake with chocolate cream cheese frosting is the move.
Sourdough Lemon Snack Cake FAQs
No — it adds a light tang that enhances the lemon flavor rather than making the cake taste sour.
A dense cake usually comes from overmixing the batter, cold ingredients, or expired leavener. Mix just until combined, use room-temperature eggs and sour cream, and make sure your baking powder and soda are fresh.
Yes — the cake is delicious plain, dusted with powdered sugar, or finished with a simple lemon glaze.
Yes, active starter works well here in place of unfed discard.
Yes — bake in a 9x13 pan and increase the bake time slightly, checking for doneness with a toothpick.
Sourdough Lemon Snack Cake Troubleshooting Guide
| Problem | Cause | Fix |
|---|---|---|
| Dense cake | Overmixed batter or cold ingredients. | Mix just until combined and use room-temperature eggs and sour cream. |
| Weak lemon flavor | Zest not bloomed, or bottled juice used. | Rub the zest into the sugar and use fresh lemon juice. |
| Buttercream slid off | Cake was frosted while warm. | Cool the cake completely before frosting. |
| Cake didn't rise | Expired baking powder/soda. | Check that your leaveners are fresh. |
| Gummy center | Underbaked. | Bake until a toothpick in the center comes out clean. |
Storage
- Store in an airtight container at room temperature for up to 2 days, or in the refrigerator for up to 5 days (because of the buttercream, refrigerate if keeping longer than 2 days).
- Let refrigerated cake sit at room temperature for 20–30 minutes before serving so the buttercream softens.
- Freeze slices tightly wrapped for up to 2 months.
Other Cake Recipes to Consider
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Sourdough Discard Lemon Snack Cake
Equipment
- 8×8 baking pan
- Parchment Paper
- Mixing bowls
- Whisk
- Rubber spatula
- Hand or stand mixer
- microplane zester
- Offset spatula
Ingredients
Sourdough Discard Lemon Cake
- 180 g all-purpose flour 1 ½ cups
- 150 g granulated sugar ¾ cup
- 6 g baking powder 1 ½ tsp
- 1 g baking soda ¼ tsp
- 3 g fine sea salt ½ tsp
- Zest of 2 lemons
- 85 g unsalted butter melted (6 tbsp)
- 30 g neutral oil 2 tbsp
- 100 g large eggs 2 eggs
- 120 g sourdough discard ½ cup
- 120 g sour cream or Greek yogurt ½ cup
- 30 g fresh lemon juice 2 tbsp
- 5 g vanilla extract 1 tsp
Lemon Buttercream
- 113 g unsalted butter softened (½ cup)
- 240 g powdered sugar 2 cups
- 15–30 g fresh lemon juice 1–2 tbsp
- Zest of 1 lemon
- 2 g vanilla extract ½ tsp
- Pinch of fine sea salt
Instructions
- Prep the pan: Preheat oven to 350°F (175°C) and line an 8x8 baking pan with parchment paper.
- Mix dry ingredients: Whisk together the flour, baking powder, baking soda, and salt.
- Make lemon sugar: Rub the lemon zest into the granulated sugar until fragrant.
- Add wet ingredients: Whisk in the melted butter, oil, eggs, sourdough discard, sour cream, lemon juice, and vanilla until smooth.
- Combine: Fold in the dry ingredients until just combined.
- Bake: Pour into the prepared pan and bake for 30–35 minutes, until a toothpick inserted in the center comes out clean.
- Cool: Let cool in the pan for 15 minutes, then transfer to a wire rack to cool completely.
- Make buttercream: Beat butter until smooth, add powdered sugar, lemon juice, zest, vanilla, and salt, and beat until fluffy.
- Frost: Spread buttercream over the cooled cake and slice.
Notes
- Store the cake in an airtight container at room temperature for up to 2 days. Because of the buttercream, it’s best to refrigerate it if keeping longer than that.
- In the refrigerator, the cake will stay fresh for up to 5 days. Let it sit at room temperature for about 20–30 minutes before serving so the buttercream softens.
- To freeze, wrap individual slices tightly and store for up to 2 months.
This releases the natural oils and gives the cake a much stronger, more vibrant lemon flavor without adding extra liquid.
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