This very blueberry, super tender layer cake is bursting with bright complementary flavors perfect for springtime! Delicate lemon sponge cake is layered with a sweet blueberry sauce, lemon blueberry mascarpone filling, and a fluffy white chocolate frosting for a show stopping cake that hits all the sweet spots. With a triple dose of blueberries and lemon, this cake is wonderfully rich and moist.
With four different components, this is certainly a celebration cake to reserve for special occasions!
Ingredients
Lemon Sponge Cake
2⅔ cups all-purpose flour
½ tsp salt
1 Tbsp baking powder
¼ cup whole milk
¾ cup sour cream
1 cup butter, room temperature
1¼ cups granulated sugar
½ cup light brown sugar, packed
4 large eggs, room temperature
1 tsp pure vanilla extract
Zest and juice of 1 lemon
Blueberry Sauce
¼ cup granulated sugar
½ cup water
1 Tbsp fresh lemon juice
1 Tbsp cornstarch
½ cup fresh blueberries
½ Tbsp butter
Lemon Blueberry Mascarpone Filling
8 oz mascarpone cheese, room temperature
Zest of 1 small lemon
2 cups heavy cream, cold
¼ cup confectioners’ sugar
½ tsp pure vanilla extract
14 oz fresh blueberries
White Chocolate Frosting
1 cup heavy cream
1 tsp pure vanilla extract
⅓ cup fresh blueberries
4 oz white chocolate, melted and cooled
Fresh blueberries (for decorating)
Directions
Lemon Sponge Cake
Preheat oven to 350°F. Grease two 9-inch round cake pans. Then line the bottoms of the pans with parchment paper and flour the sides of the pan; set aside.
In a medium bowl, whisk together the flour, salt, and baking powder; set aside.
In a small bowl, whisk together the milk and sour cream; set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter until light and fluffy. Gradually add both sugars and beat until combined. Add the eggs, one at a time, scraping down the sides of the bowl and beating well after each addition. Then add in the vanilla, lemon zest and juice, and mix until incorporated.
With the mixer on low speed, add the flour mixture in three additions, alternating with the milk mixture, beginning and ending with the flour mixture. Be sure to scrape down the sides of the bowl as needed, and be careful not to overmix the batter.
Evenly divide the batter into the prepared pans and spread to the edges using an offset spatula. Bake for 25-30 minutes, or until the cakes are golden brown and a toothpick inserted in the center comes out clean.
Cool the cakes for 10 minutes, then remove from the pans by running a knife around the edges and inverting each cake onto a plate. Be sure to remove the parchment paper. Allow the cakes to cool completely before assembling.
Blueberry Sauce
In a small saucepan, combine the sugar, water, lemon juice, and cornstarch, and heat until simmering, stirring constantly. Add the blueberries and simmer for 10 minutes, or until the blueberries begin to pop. Use a fork to lightly crush the blueberries, but not puree. Stir in the butter until melted.
Remove the mixture from the heat, and set aside to cool completely.
Lemon Blueberry Mascarpone Filling
In a large bowl using an electric mixer, cream together the mascarpone and lemon zest; set aside.
Pour the cream into a chilled bowl and use an electric mixer to beat the cream with the sugar until soft peaks form. Then add the vanilla extract and beat until incorporated.
Using a rubber spatula, gently fold the whipped cream into the mascarpone mixture just until incorporated. Then gently fold in the blueberries.
White Chocolate Frosting
Pour the cream into a chilled bowl and use an electric mixer to beat the cream with the vanilla until soft peaks form. Using a rubber spatula, gently fold in the blueberries and melted chocolate until incorporated.
Assembly
Use a large serrated knife to remove the domes from the top of each cake so the layers are flat. Then cut each cake in half so you have four equal layers.
Place the first layer of cake on a serving plate, cake stand, or cardboard cake circle, and evenly brush with the blueberry sauce. Then spread ⅓ of the filling on top of the cake. Repeat this with the next two layers. Place the fourth layer on top. The top layer does not get the blueberry sauce or filling.
Evenly spread the frosting on top of the cake. Chill the cake in the refrigerator until the frosting sets, then decorate as desired.