Kumquat Citrus Olive Oil Cake with Swiss Meringue Buttercream
Bright, zesty, and irresistibly moist, this Kumquat Citrus Olive Oil Cake with Swiss Meringue Buttercream is the perfect blend of fresh citrus flavor and delicate sweetness. Made with whole kumquats, heart-healthy olive oil, and silky Swiss meringue buttercream, this elegant dessert is a must-try for citrus cake lovers and special occasions alike.
What do kumquats taste like in cake?
Kumquats add a bright, tangy-sweet flavor with a slight bitterness from the peel, which balances beautifully with the sweetness of the cake and buttercream.
Do you use the whole kumquat in the recipe?
Yes, the entire kumquat—peel and all—is typically used, as the peel contains natural sweetness and aromatic oils that enhance the citrus flavor.
Can I substitute kumquats with another citrus fruit?
If kumquats aren’t available, you can use a mix of orange and lemon, though the flavor will be less complex and slightly less tart.
Why use olive oil instead of butter in this cake?
Olive oil creates a moist, tender crumb and adds a subtle fruity depth that pairs especially well with citrus flavors.
Is Swiss meringue buttercream too sweet?
Swiss meringue buttercream is less sweet than traditional buttercream, with a smooth, silky texture that complements the tangy citrus cake.
Can I make this cake ahead of time?
Yes, the cake layers can be baked in advance and stored tightly wrapped, while the buttercream can be made ahead and re-whipped before use.
How should I store the finished cake?
Store the cake in the refrigerator due to the buttercream, but bring it to room temperature before serving for the best texture and flavor.
Bake with me!
Kumquat Citrus Olive Oil Cake with Swiss Meringue Buttercream
Ingredients
for the citrus olive oil cake:
- 2 cups all purpose flour
- 2 teaspoons baking powder
- 1/2 teaspoon fine sea salt
- 1/4 teaspoon baking soda
- 1 cup granulated cane sugar
- zest of 1 lemon
- zest of 1 orange
- 1/2 cup extra virgin olive oil
- 3 large eggs
- 1/3 cup fresh orange juice
- 3/4 cup sour cream
- 1 1/2 teaspoons vanilla extract
- 1/2 cup finely chopped kumquats
- 2 tablespoons granulated cane sugar
for the kumquat compote:
- 1 cup kumquats sliced into thin rounds or chopped
- 1/3 cup granulated cane sugar
- 3/4 cups fresh orange juice plus 2 tablespoons
- 2 tablespoons fresh lemon juice
for the Swiss meringue buttercream:
- 3 egg whites
- 3/4 cup granulated cane sugar
- 1/2 cup unsalted butter cubed, softened but still slightly firm
- 1 teaspoon vanilla extract
- 1/8 teaspoon fine sea salt
- fresh raspberries for decorating
Instructions
to make the citrus olive oil cake:
- Preheat oven to 375F. Butter a 9″ springform pan and line the bottom with parchment paper. Set aside.
- In a large bowl, combine the flour, baking powder, salt, and baking soda. Mix well. Set aside.
- In a separate large bowl, combine the 1 cup sugar, lemon zest, and orange zest. Rub together with your fingers for 30 seconds to release the essences.
- Add the olive oil and eggs to the bowl to whisk vigorously for 1-2 minutes, until fluffy and pale yellow in color.
- Whisk in the fresh orange juice, sour cream, and vanilla extract until smooth.
- Add the dry ingredients and mix just until smooth. Be careful not to over mix the batter or the cake can turn out dense.
- In a small saucepan over medium heat, combine the finely chopped kumquats and remaining 2 tablespoons sugar. Stir to combine, then occasionally stir to keep from burning as the kumquats caramelize, about 3-5 minutes. Add to the cake batter and stir to combine.
- Transfer the cake batter to the prepared springform pan.
- Bake for 5 minutes, then reduce heat to 350F to bake 30-35 minutes, or until a toothpick inserted into the center comes out clean. Let cool in the pan 10 minutes before transferring to a wire rack to cool completely.
to make the kumquat compote:
- Combine the kumquats, sugar, and orange juice in a saucepan over medium heat. Stir until it begins to bubble, then occasionally stir to prevent any burning. Cook down until thickened, about 10-12 minutes. Transfer to a high speed blender with 2 tablespoons more orange juice to help loosen up. Pour back into the saucepan and stir in the lemon juice. If the compote is runny, stir over medium heat for another 1-2 minutes, until slightly thickened to a jam-like texture. Let cool completely. It will continue to thicken as it cools.
to make the Swiss meringue buttercream:
- Add 2″ of water to a saucepan over medium high heat. Bring to a boil, then reduce heat to medium. In a large bowl (that would easily sit on top of the saucepan without touching the water), combine the egg whites and sugar. Place over the simmering water and whisk until all sugar is dissolved, about 5-10 minutes. Rub the mixture between your fingers to double check for any texture, as it is done when completely smooth.
- Pour the mixture into the bowl of your stand mixer fitted with the whisk attachment. Beat for 10-15 minutes, until stiff peaks. Place in the fridge for 10-20 minutes to cool down completely. Place back on the stand mixer to beat in the cubed butter until a thick, but velvety buttercream, about 2-3 minutes. Fold in the vanilla and salt with a spatula.
to assemble the cake:
- Use an offset spatula to frost the cooled cake with the swiss meringue buttercream. Spoon the kumquat compote on top and swirl into the buttercream. Decorate with fresh kumquats and raspberries to enjoy!
I truly hope you all enjoy this treasured recipe that has nestled its way into our hearts here in the ABM kitchen! ’till next time… xxL
“For I know the plans I have for you,” declares the Lord, “plans to prosper you and not to harm you, plans to give you hope and a future.” ~ Jeremiah 29:11 NIV
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Soo good perfect summer cake.
Thank you for sharing this recipe
Omg so good!! Made this for my birthday and everyone loved it!!
awe this is so fun!! happy birthday Hannah!!!
Thank you for sharing this recipe