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Picture of a slice of sourdough lemon snack cake.

Sourdough Discard Lemon Snack Cake

Audrey
This Sourdough Discard Lemon Snack Cake is soft, buttery, and full of bright lemon flavor. Finished with a creamy lemon buttercream, it’s an easy 8x8 cake perfect for spring or everyday baking.
Prep Time 30 minutes
Cook Time 30 minutes
Decorating time 15 minutes
Total Time 1 hour 15 minutes
Course Dessert
Cuisine American
Servings 9
Calories 495 kcal

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

Storage
  • 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.
Audrey's tip: Rub the lemon zest into the sugar.
This releases the natural oils and gives the cake a much stronger, more vibrant lemon flavor without adding extra liquid.

Nutrition

Calories: 495kcalCarbohydrates: 65gProtein: 5gFat: 22gSaturated Fat: 13gPolyunsaturated Fat: 2gMonounsaturated Fat: 6gTrans Fat: 1gCholesterol: 92mgSodium: 246mgPotassium: 29mgFiber: 1gSugar: 43gVitamin A: 550IUCalcium: 48mgIron: 1mg
Keyword cake, sourdough discard
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