For a quintessential summer flavor, I went to Half Baked Harvest once more for her Bursting Blueberry Lemon Layer Cake and it did not disappoint. It also gave me an opportunity to practice both my food photography and cake frosting skill (both of which I’ve been trying to practice since we’ve been sheltering in place.

Ingredients

Cake

1 cup melted coconut oil (can use melted butter or canola oil)
1/2 cup plain greek yogurt
3 large eggs, at room temperature
1 1/2 cups granulated sugar
1/4 cup brown sugar, packed
1 tablespoon vanilla extract
1 cup buttermilk
1/2 cup fresh lemon juice
1 tablespoon lemon zest
3 3/4 cups + 1 tablespoon all-purpose flour
2 teaspoons baking powder
1 teaspoon baking soda
1 teaspoon kosher salt
1 cup high-quality blueberry jam
2 cups fresh or frozen blueberries (do not thaw using frozen)

Blueberry Buttercream

3 sticks salted butter, at room temperature
4 ounces mascarpone or cream cheese, at room temperature
3 cups powdered sugar
4-5 tablespoons high-quality blueberry or blackberry jam

Instructions

Preheat oven to 350 degrees F. Grease 3 (8-inch) round cake pans. Line with parchment paper, then butter/spray with cooking spray. I ended up testing this out with 4 (6-inch) round cake pans.
In the bowl of a stand mixer beat together the coconut oil, yogurt, eggs, sugar, brown sugar, vanilla, buttermilk, lemon juice, and zest. Add 3 3/4 cups flour, baking powder, baking soda, and salt. Mix until just combined.
Toss the blueberries with the remaining 1 tablespoon flour and fold them into the batter – this keeps them from sinking to the bottom of your batter. Swirl in the blueberry jam, leaving a few streaks of jam throughout the batter, it shouldn't be fully incorporated.
Pour the batter among the 3 cake pans and bake 30-35 minutes, until the tops are just set and no longer wiggly in the center. Remove and let cool five minutes, then run a knife around the edges of the pan and turn the cakes out onto a cooling rack. Cover and let the cakes cool completely before assembling.
To make the buttercream. Add the butter, mascarpone, and powdered sugar to the bowl of a stand mixer. Beat the butter and powdered sugar together until the butter is light and fluffy. Divide the buttercream between 3 bowls. Mix 1-2 tablespoon jam into 1st bowl, then 2-3 tablespoons jam to the 2nd bowl. Leave the 3rd bowl plain. I ended up skipping the blueberry jam, it felt really blueberry heavy already and I wanted a smoother frosting.
To assemble, place one cake layer on a serving plate or cake stand. Spread the buttercream over the cake. Add the 2nd cake layer and spread with the buttercream again. Add the final cake layer and spread with the white buttercream. Lightly frost the outside of the cake.