Sourdough Lemon Cake (Our Family Birthday Tradition!)

Every May, when the garden starts waking up and the sunshine lingers a little longer, I find myself pulling out this well-loved recipe card for my husband’s favorite birthday treat, Sourdough Lemon Cake.

Lemon is his absolute favorite flavor, lemon cookies, lemon bars, lemon curd,he loves them all. But nothing compares to this cake. It’s become our little tradition: me baking this vibrant, tangy cake while he grills dinner and my son sneaks frosting from the mixing bowl. It’s the kind of recipe that brings everyone into the kitchen, just like our sourdough granola bars and sourdough banana bread do on slower mornings or snack-filled afternoons.

If you’re looking for a way to use up your sourdough discard and brighten up someone’s day (birthday or not), this cake is for you.

Why You’ll Love This Sourdough Lemon Cake

This cake is:

• Bright and tangy thanks to lemon juice and zest
• Moist and tender from the sourdough discard and milk
• Perfectly sweet, balanced by the creamy lemon buttercream icing
• A delicious way to use sourdough discard
• A great make-ahead birthday cake or springtime dessert

Even if you’re new to baking with sourdough, this cake is incredibly forgiving, no fermentation needed, just use your discard and bake as usual!

Ingredients

For the Cake:

• 3 cups sifted all-purpose flour (350g)
• 2 teaspoons baking powder
• ½ teaspoon baking soda
• 1 teaspoon salt
• 1 cup milk (250g)
• 1 cup sourdough discard (280g)
• ½ cup fresh lemon juice (about 2 lemons)
• 1 cup butter, room temperature (2 sticks)
• 2 cups sugar (384g)
• 1 tablespoon lemon zest (about 2 lemons)
• 2 teaspoons vanilla extract
• 3 large eggs, room temperature

For the Lemon Buttercream Frosting:

• 1 cup butter, room temperature (2 sticks)
• 4 cups powdered sugar (540g)
• 2 tablespoons fresh lemon juice
• 2 tablespoons heavy cream
• Optional: lemon zest for garnish
• Pinch of salt

Instructions

Step 1: Prep Your Oven and Pans

Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans or line them with parchment paper circles.

Step 2: Sift the Dry Ingredients

In a medium bowl, sift together the flour, baking powder, baking soda, and salt. Set aside.

Step 3: Mix the Wet Ingredients

In a separate bowl, combine the milk, sourdough discard, and lemon juice. Whisk together and let it sit while you cream the butter and sugar.

Step 4: Cream the Butter and Sugar

In a large mixing bowl, beat the butter until light and fluffy, about 2–3 minutes. Add the sugar and lemon zest, and continue beating until pale and fluffy, another 3 minutes.

Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

Step 5: Combine Everything

Alternate adding the flour mixture and the milk/sourdough/lemon mixture to the creamed butter and sugar. Start and end with the flour, mixing just until combined. Be careful not to overmix.

Step 6: Bake

Divide the batter evenly between the two prepared pans. Bake for 30–35 minutes, or until a toothpick inserted into the center comes out clean.

Let the cakes cool in the pans for 10 minutes, then turn them out onto a wire rack to cool completely before frosting.

Lemon Buttercream Frosting

In a large bowl, beat the butter until creamy. Slowly add powdered sugar, one cup at a time, mixing well after each addition. Add the lemon juice, cream, salt, and optional zest. Beat for 3–5 minutes until the frosting is fluffy and spreadable.

If your frosting is too thick, add a little more cream. If it’s too thin, add more powdered sugar.

Assemble the Cake

Once the cakes are completely cool, spread a layer of frosting on the bottom layer. Place the second layer on top and frost the entire cake. For a rustic look, keep it simple. For a birthday cake, decorate with extra lemon zest, candied lemon slices, or edible flowers.

Tips for Success

• Don’t overmix. Once the dry ingredients are incorporated, stop mixing to avoid a tough cake.
• Fresh lemons! Bottled juice won’t have the same vibrant flavor.
• Sourdough discard should be unfed. It doesn’t need to be active; discard straight from the fridge works fine.
• Let it cool completely before frosting. Otherwise, the buttercream will melt.

Make-Ahead & Storage Tips

• Make ahead: Bake the cake layers a day in advance, wrap tightly, and refrigerate or freeze until ready to frost.
• Storage: Keep the frosted cake covered at room temperature for up to 2 days or refrigerate for 5 days.
• Freezing: Wrap unfrosted layers tightly and freeze for up to 3 months.

Frequently Asked Questions

Can I make this cake without sourdough discard?
Yes! Substitute the sourdough discard with ½ cup plain yogurt or sour cream. The texture will be slightly different, but still delicious.

Can I turn this into cupcakes?
Absolutely! This recipe makes about 24 cupcakes. Bake at 350°F for 18–22 minutes, or until a toothpick comes out clean.

What if I want a stronger lemon flavor?
You can add a teaspoon of lemon extract or more zest to both the cake and frosting. Lemon lovers, rejoice!

Is this cake fermented like other sourdough recipes?
No fermentation here, this is a quick sourdough discard recipe. It gives the cake moisture and a slight tang, but no long fermentation is needed.

A Slice of Spring, Every Year

This sourdough lemon cake has become a birthday dessert tradition for our family every year!

If you give this cake a try, I’d love to hear how it turns out. Whether it becomes your family’s birthday staple or a springtime favorite, it’s a cake worth baking again and again.

Let me know in the comments below and happy baking! God Bless.

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