Rosemary Sponge Cake with Apricot Compote and White Chocolate Buttercream
This light and classic Rosemary Sponge Cake is layered with rosemary infused apricot compote and white chocolate buttercream frosting. Dehydrated lemons and rosemary make decoration easy and beautiful.
Ingredients
Rosemary Sponge Cake
- 217 grams granulated sugar 1 cup + 1 tablespoon sugar
- 140 grams fine pastry or cake flour, measured and then sifted twice 1 cup fine pastry or cake flour
- 335 grams eggs*, at room temperature 7 to 8 medium sized eggs
Rosemary Simple Syrup
- 2 rosemary strands
- 1/2 cup granulated sugar
- 1/2 cup water
Apricot Compote
- 406 grams apricots, cut in half and pits removed about 1 pound apricots, a little less
- 1/2 cup turbinado (raw) sugar
- 2 rosemary strands
- 1 ounce limoncello
- sea salt or Himalayan salt, to taste
White Chocolate Buttercream
- 4 and 1/2 tablespoons flour
- 1 cup granulated sugar
- 1 cup whole milk
- 2 rosemary strands
- 1 cup unsalted butter, cubed and at room temperature
- 12 ounces white chocolate melting wafers
- sea salt, to taste
Cake Assembly
- dehydrated lemon slices*
- rosemary strands
Instructions
Rosemary Sponge Cake
- Place the oven rack in the lower third of the oven and preheat to 350 degrees Fahrenheit. Line the bottoms of two 9 inch cake pans with parchment paper.
- Add the egg whites to a large stainless steel or glass bowl with half of the sugar. Beat on medium speed until stiff peaks form.
- Add the egg yolks to a stainless steel or glass bowl. Add the rest of the sugar and beat until double in volume.
- Fold the egg yolk mixture into the egg whites.
- Sift 1/4 cup of the flour over the top of the egg mixture and gently fold with a large rubber spatula until there are just a few streaks of flour remaining. Repeat with the remaining flour a 1/4 cup at a time.
- Pour into the prepared pans and bake for 30 minutes or until a toothpick inserted in the middle comes out clean. Let the cakes cool for 10 minutes in their pans and then transfer them to cooling racks.
- Let them cool completely before frosting them. Or before wrapping them up tight in plastic wrap and foil for storing in the freezer or fridge. The night before frosting, take the cake layers out of the freezer and let them thaw out in the fridge overnight (still wrapped up). Then take them out of the fridge (still wrapped up tight) and let them come to room temperature before frosting.
Rosemary Simple Syrup
- Dissolve the sugar and water in a small saucepan over medium-high heat until clear. Add the rosemary strands and simmer for 20 minutes. Strain the syrup into an air tight container and bring to room temperature before covering and storing in the fridge.
Apricot Compote
- Add the pitted apricots, turbinado sugar, and rosemary to a medium sauce pan over medium heat. Simmer for 20 minutes, using a wooden spoon to mash the apricots, breaking them apart.
- Take the rosemary out. Add the limoncello and salt. Use an immersion blender to puree the apricots until fairly smooth.
- Simmer on medium heat for 10 to 15 more minutes until the apricot compote has darkened slightly and thickened up a little.
- Cool completely and store in an air tight container for later use. You should have about 2 to 2.5 cups.
White Chocolate Buttercream
- Melt the white chocolate in a glass bowl in 20-second intervals in the microwave. Set aside to cool.
- In a medium saucepan over low heat, combine the flour, sugar, and milk, stirring constantly. Once the sugar and flour are dissolved, add the rosemary and continue stirring. It will take a while to start to boil cooking on low but once it starts, the pudding will thicken up really quick. Cook for one minute after the mixture has started to boil, stirring continually.
- Take the pudding off the heat and pour it into a fine-mesh sieve over a shallow plate, straining out all the rosemary. Press plastic wrap directly on top of the pudding’s surface and let it cool to room temperature.
- In a mixing bowl, beat the butter until creamy. Pour in the cooled melted white chocolate and beat until the butter is fluffy.
- Add the cooled pudding a tablespoon at a time, mixing until smooth each time.
Cake Assembly
- If you made the cakes the night before, take them out of the refrigerator and let them come to room temperature. Or wait until the cakes have cooled completely. Place one cake on a portable flat surface like a cardboard cake round, the bottom side of a plate, or anything else you have on hand. I used a round wooden surface.
- Place that on top of a cake turntable or use your microwave plate and wheel to make a turntable (just take the wheel off, place it on the counter, and then put the microwave plate back on top of it). If you feel it’s necessary, you can even out your cakes before moving on.
- Use a pastry brush to coat the top of the cake with the rosemary simple syrup.
- Put some frosting in a pastry bag with a round tip (I used 2A). Pipe a protective border around the edge of the cake.
- Spread the apricot compote onto the cake, making sure it doesn’t get higher than the frosting border you piped.
- Place the second cake layer on top, lining it up carefully. Repeat steps 3-5 until you have all your layers done.
- Place 1 cup of frosting on top of the cake and start spreading it out in a thin layer, using a pastry scraper and the turntable to spread the frosting around. It’s okay if crumbs get loose and it’s messy-it’s the crumb coat. You should be able to see the cake peeking through the frosting. Use more frosting if necessary.
- Put the cake in the fridge for 30 minutes to allow the crumb coat to set.
- Take the cake out again, place it on the turntable and add big dollops of frosting all around. Take a pastry scraper, hold it vertically and at a slight angle to the cake, and start turning the cake around. Keep going until excess frosting no longer coats the scraper and the cake is smooth.
- Garnish with dehydrated lemon slices* and strands of rosemary.
- Store the cake covered at room temperature or in the fridge for 3 to 5 days.
Notes
The cake recipe makes two 9-inch cake layers and there is enough frosting to frost a 2-layer cake. Double the frosting recipe if you decide to make a 4-layer cake like the one pictured. There will be leftover frosting but I don’t think a single batch of frosting would be enough to frost the whole cake sufficiently.
Eggs
When baking by weight, eggs can be a little difficult but you should be fine with 7 to 8 medium eggs (which can weigh anywhere from 53 to 63 grams).
Dehydrating Lemons
I used a mandolin to cut lemons into 1/16-inch slices and laid them out on my dehydrator trays. Leave space between each lemon slice to ensure they aren’t overcrowded.
I did mine on high for 2 hours or so and then let them go overnight on low. There’s no exact science. Just check on the lemons occasionally. They are done when they are no longer moist but have a slightly tacky feel. You can also use an oven preheated to 200 degrees Fahrenheit.