As flavor combinations go, blueberry and lemon is easily one of my favorites. This cake represents all that is good with that combination: the violet sweetness of blueberries, tart lemon curd, and a sweet lemon frosting. What’s not to love?
The cake is a straightforward vanilla cake with lemon zest and blueberries folded in. Be careful to fold the berries gently so that they stay whole.
I’ll admit that I’m going to cheat and use store-bought lemon curd. If I have time, I like to make a fresh batch, but I’m in a bit of a pinch for this cake. I brighten up the store-bought curd by whisking in some fresh lemon juice and lemon zest; this also makes it easier to spread.
For the frosting, I like to use an Italian Meringue Buttercream, where a hot simple syrup is slowly poured into whipping egg whites. Butter is then added for a creamy, smooth frosting that spreads like a dream. For this cake, I plan to flavor it with lemon extract for a light, bright flavor that won’t overpower the blueberry cake. I also want the frosting to stand out from the curd.
- 2 1/2 cups all-purpose flour
- 2 tsp baking powder
- 3/4 tsp baking soda
- 1/2 tsp salt
- 1/2 cup butter, melted and cooled
- zest of 1 lemon
- 1 1/2 cups sugar
- two 6-oz containers vanilla yogurt
- 3 eggs
- 1/2 tbsp vanilla
- two 6-oz containers of blueberries
Preheat oven to 325 degrees F. Butter and flour two 9-inch round cake pans.Rinse one container of blueberries (plus about a quarter of the second container) under water, and dry them gently on paper towels. Toss in a tablespoon of flour just to coat. Reserve the remaining blueberries for decoration.
In a large bowl, sift together the dry ingredients.
In a separate bowl, whisk together the butter, lemon zest and sugar. Whisk in the vanilla yogurt, followed by the eggs, one at a time. Finally, whisk in the vanilla and mix until everything is homogeneous. Pour the dry ingredients on top of the wet and whisk in just until incorporated. Fold in the blueberries, being careful not to break them.
Divide the batter between the two pans and bake in the preheated oven for 30 – 35 minutes until the edges are beginning to lightly brown, and a toothpick inserted in the center comes out clean. Let the cakes rest in their pans for 10 minutes before removing them to wire racks to cool completely.
Lemon Italian Meringue Buttercream
Warning: Italian Meringue Buttercream is a little tricky and takes some practice to get the timing down. Ideally, you want your egg whites to be at stiff peaks right around the time your sugar syrup reaches 245 degrees. If not, you want your egg whites done early; they can continue to be whipped at low speed to prevent weeping. When you add the butter, the frosting may break; just keep going and it will sort itself out. In spite of some pitfalls, this is a pretty forgiving recipe.
- 5 egg whites
- 12 oz granulated sugar (about 1 1/2 cups), divided
- 1/4 cup cold water
- 2 cups salted butter, at room temperature
- 1 1/2 tsp vanilla
- 2 tsp lemon extract
- 4 tbsp lemon juice
Place 1 1/4 cups of the sugar in a pan along with the cold water. Reserve the remaining 1/4 cup of sugar for the egg whites. Place the pan over medium-high heat, stirring to help dissolve the sugar. Once it begins to boil, place a candy thermometer and boil until it reaches 245 degrees F. It will take a few minutes to achieve that temperature, so once it boils, start the next step.
Place the 5 egg whites in the bowl of a stand mixer. Begin beating the egg whites at medium-high speed to soft peaks. With the mixer running, gradually add in the reserved 1/4 cup sugar. Continue to beat to stiff peaks. At this point, the sugar syrup should be at temperature.
With the mixer running at full speed, pour the hot sugar syrup into the egg whites in a slow steady stream. Beat the meringue until the bottom of the bowl is cool to the touch, about 7-10 minutes at high speed.
Once the meringue has cooled, you’re ready to incorporate the butter and flavorings. On high speed, add the butter 1 tablespoon (roughly) at a time. Once it’s all incorporated, the frosting may break. Just keep beating until it comes together. Add in the vanilla, lemon extract, and lemon juice, beating to combine and continuing to beat if it breaks. Taste and add more juice/extract as needed to achieve the lemon flavor you want. The amounts above worked great for me, but sometimes out-of-season lemon juice can be lackluster.
Frosting and Assembly
Lemon curd is a delicious filling, but it can make for a wobbly cake if not handled properly. Begin by piping a ring of the buttercream frosting around the bottom cake layer. Refrigerate for about 20 minutes to allow the frosting to set up a bit. Fill the cavity with lemon curd and stack the layers carefully.
Frost the top and sides of the cake. A cake turner and an offset spatula will help you achieve smooth sides and a top. I decided to decorate with lemon curd and blueberries; it’s a bit amateur-ish, but I like to decorate with items that represent the flavors of the cake.