Blueberry Swirled Lemon Cake
A stunning lemon sheet cake swirled with homemade blueberry compote, topped with silky lemon Swiss Meringue Buttercream, fresh lemon curd, and blueberries. This elegant yet approachable dessert delivers bright citrus flavor, juicy berry ribbons, and a velvety crumb perfect for spring and summer gatherings.
Equipment
- 9x13-inch baking pan
- medium saucepan
- mixing bowls
- stand mixer
- double boiler
- wire cooling rack
- Offset Spatula
Ingredients
- 2 cups fresh blueberries
- 1/4 cup granulated sugar
- 2 tbsp fresh lemon juice
- 1 pinch salt
- 1/4 cup granulated sugar
- 2 tbsp cornstarch
- 3/4 cup water
- 3 egg yolks
- 1 tbsp lemon zest
- 3 tbsp fresh lemon juice
- 1 1/2 cups granulated sugar
- 1 tbsp lemon zest
- 2 1/2 cups all-purpose flour
- 2 tsp baking powder
- 1/2 tsp baking soda
- 1/2 tsp salt
- 3/4 cup buttermilk
- 1 cup vegetable oil
- 3 large eggs
- 1/4 cup fresh lemon juice
- 1 tsp vanilla extract
- 4 egg whites
- 1 cup granulated sugar
- 2 cups unsalted butter, softened
- 1/3 cup lemon curd
- 1 pinch salt
- 1/2 cup fresh blueberries for garnish
Instructions
- Combine blueberries, sugar, lemon juice, and salt in a saucepan. Bring to a boil, mash about half the berries, then simmer for 8 to 10 minutes until thickened. Transfer to a shallow bowl and cool completely.
- Whisk sugar and cornstarch in a saucepan. Stir in water and egg yolks until smooth. Bring to a boil while stirring until thickened, then remove from heat and whisk in lemon zest and lemon juice. Cool completely.
- Preheat the oven to 350°F (175°C). Grease and line a 9x13-inch baking pan with parchment paper.
- Rub lemon zest into the sugar with your fingertips. Whisk in flour, baking powder, baking soda, and salt.
- In another bowl whisk together buttermilk, vegetable oil, eggs, lemon juice, and vanilla extract.
- Pour the wet mixture into the dry ingredients and stir until just combined.
- Spread half of the batter into the pan. Dollop 6 teaspoons of blueberry compote over the batter and swirl lightly with a knife. Add remaining batter and repeat with 6 more dollops. Reserve 1/4 cup compote for decorating.
- Bake for 28 to 32 minutes, rotating halfway through baking, until a toothpick inserted into the center comes out clean. Cool for 10 minutes in the pan, then transfer to a wire rack to cool completely.
- Whisk egg whites and sugar over a double boiler until the mixture reaches 160°F (71°C). Transfer to a mixer and whip to stiff peaks while cooling.
- Switch to the paddle attachment and add softened butter 1 to 2 tablespoons at a time until fully incorporated. Mix in lemon curd and salt until silky smooth.
- Frost the cooled cake. Dollop the reserved blueberry compote over the frosting and lightly swirl. Add spoonfuls of lemon curd and scatter fresh blueberries over the top before serving.
Notes
Allow both the blueberry compote and lemon curd to cool completely before using. Avoid over-swirling the compote to preserve distinct blueberry ribbons throughout the cake. If the Swiss Meringue Buttercream appears curdled while adding butter, continue mixing and it will become smooth. Store covered in the refrigerator for up to 3 days and bring to room temperature before serving.