A lemon blueberry ombre cake, made of four layers of zesty lemon cake with fresh blueberry jam and swiss meringue buttercream in three shades of blueberry.
Everybody loves an ombre cake. How can you resist? There’s something about the monochromatic fade-out of multiple shades of frosting that is simply appealing to the eye. Bonus points for frosting that is naturally dyed by the flavors already involved in the cake. In today’s case, our buttercream gets it’s lovely purple hues from a fresh blueberry jam.
I’m generally not a fan of artificial food coloring, for many reasons – most of which are related to health. But besides all that, why wouldn’t we want to take advantage of the amazing colors that nature hands us as they come? In the summer, we have so many berries and fresh fruits in vivid reds and blues and purples. I want to smash them all up and blend them into every glaze and buttercream I make. I mixed raspberries with cream cheese frosting for my Raspberry Chocolate Mini Cake. The Strawberry Rhubarb Brown Butter Cake got a little light pink strawberry drizzle. And, those delicious homemade sweet rolls were smothered in a crimson blood orange frosting.
It’s hard not to do. I bake with the seasons. A lot of produce and herbs and flowers are used. Many of them have stunning colors. And I want to help them show off their beauty.
So today, let’s focus on the beauty of antioxidant-rich blueberries. It’s those good-for-you micronutrients that make them such a rich color. We’ll make a very simple blueberry jam. Then we’ll whip up a batch of silky-smooth swiss meringue buttercream. The buttercream will be dolloped into little bowls and mixed with different amounts of blueberry jam to create varying shades of purple. We will feel like artists as we decorate our cake, surrounded by colors and piping bags and spatulas.
An ombre cake may look impressive, but if you’ve got a turn table, a piping bag and a bench scraper, it may be easier than you think. After your cake has been crumb-coated and chilled, just fill piping bags with each type of frosting. Pipe a few layers of each color, working your way around the cake. Start with the darkest shade on the bottom, ending with the lightest shade for the top of the cake. Place your bench scraper vertical, parallel with the cake, and press into the frosting lightly. Now, begin to rotate the turn table as you hold the bench scraper in place, until you’ve made it all the way around. Smooth the top of the cake, and you’ve arrived.
The most important part is to have fun, eat lots of cake scraps dipped in leftover jam, and enjoy your lovely masterpiece.
Lemon Blueberry Ombre Cake
Four layers of zesty lemon cake with fresh blueberry jam and swiss meringue buttercream in three shades of blueberry.
- 3 ounces unsalted butter room temperature
- 3/4 cup sugar
- 1 lemon zested
- 1 tbsp fresh lemon juice
- 3 eggs
- 1/3 cup whole milk
- 1 tsp vanilla
- 1 1/4 cup flour
- 1 1/2 tsp baking powder
- 1 1/2 cups fresh or frozen blueberries
- 3 tbsp sugar
- 1 tsp fresh lemon juice
- 1/2 cup sugar
- 1/2 cup water
- 1/4 cup fresh lemon juice
- 3 egg whites
- 1/2 cup sugar
- 8 ounces unsalted butter room temperature
for the lemon cake:
Preheat oven to 350 F. Butter two 6" cake pans and line bottoms with parchment.
In the bowl of a stand mixer fitted with the paddle attachment, combine sugar, lemon zest, and juice; mix for a minute or so, until fully incorporated. Add butter; cream until fluffy, 1-2 minutes. Add eggs, one at a time, scraping sides of bowl with a spatula after each addition. Add milk and vanilla, mixing thoroughly. Pour in flour and baking powder and mix until just combined. Divide batter evenly among prepared pans. Bake until toothpick inserted in center comes out clean, about 25-30 minutes. Allow to cool completely.
for blueberry jam:
Combine berries, sugar, and lemon juice in a saucepan. Cook over medium heat, stirring constantly, until thickened - about 8-10 minutes. Taste and adjust for sugar as desired. Allow to cool completely; puree in a food processor until relatively smooth.
for the syrup:
In a heavy-bottomed saucepan, combine sugar and water. Bring to a boil; boil 1-2 minutes, until sugar is dissolved. Remove from heat and pour into a clean container. Whisk in lemon juice. Cool.
for the swiss meringue buttercream:
In a stainless steel bowl, combine sugar and egg whites. Place over a double boiler on medium heat. Cook, whisking frequently, until warm to the touch and sugar is dissolved (it will feel smooth between your fingers). Pour into the clean bowl of a stand mixer fitted with the whisk attachment. Whisk on medium-high until cooled slightly. Add butter, a tablespoon at a time. Continue to whisk a minute or two, until buttercream is smooth and fluffy.
Slice each cake in half horizontally. With a pastry brush or spoon, soak three of the layers with the lemon syrup. On the bottom round, spread about 1/3 cup of buttercream in an even layer, followed by an equal amount of blueberry jam. Stack next cake on top and repeat process with next two layers. Add top layer of cake and press gently to adhere. Apply a thin layer of buttercream over entire cake to crumb coat; chill 20-30 minutes.
Set about half of remaining buttercream aside. Split the rest in half, dividing into two small bowls. Add one tablespoon of pureed blueberry jam to one bowl; whisk to combine. Add one teaspoon to the other bowl; whisk to combine. You will now have 3 shades of buttercream.
Pipe darkest shade of buttercream around the bottom of the cake. Pipe lighter shade next, circling around cake until frosting is gone. Finish with the plain buttercream around the top. Smooth with a bench scraper or spatula.
Cake is best served at room temperature.