Lemon Blueberry Mascarpone Cake

This Lemon Blueberry Mascarpone Cake is a layer cake made with a base of lemon blueberry olive oil cake, a lemon curd filling, and a simple mascarpone frosting.

Lemon Blueberry Cake

• Extra Virgin Olive Oil: Use extra virgin olive oil for this cake. I really enjoy Spanish or Italian extra virgin olive oil from Costco or Trader Joe’s. The flavor is not overpowering and works really well in cakes, like this Italian Olive Oil Cake, but also works well in dinner recipes too. You can use vegetable oil if needed, but for best results I recommend extra virgin olive oil.
• Whole Milk: Whole milk has a higher fat content than 1 or 2% but in a pinch you can use 1 or 2% milk.
• Eggs: Use large eggs, pasture-raised if possible.
• Vanilla Extract: Use real vanilla extract, not imitation vanilla. Costco sells a large bottle that is less expensive per volume than most other places.
• Granulated Sugar: Adds sweetness.
• Lemon Zest & Juice: Zest the lemon before juicing it. It is the zest that adds the most flavor. Use the finest grate of a box grater or a zester and zest only the brighter most yellow part of the lemon (not the white pith).
• Baking Powder: For leavening
• Salt: To bring out flavor.
• Flour: Use all purpose, unbleached flour.
• Blueberries: I recommend fresh blueberries rather than frozen blueberries, though any fresh berries would be great.

Lemon Curd

• Egg Yolks: From large eggs.
• Lemon Zest and Juice: See notes above.
• Granulated Sugar: To balance tartness from the lemons
• Salt: To balance flavor.

Mascarpone Frosting

• Mascarpone: Similar to cream cheese in texture, but milder in flavor. Cream cheese can be used 1 for 1 as a substitute.
• Butter: I use salted butter.
• Powdered Sugar: Use powdered sugar rather than granulated sugar.
• Vanilla Extract: Adds a subtle creamy flavor.

Step 1. Preheat, Prepare Pan: Preheat the oven to 350°F. Butter and flour two 8-inch round cake pans.

Step 2. Combine Wet Ingredients: In a large bowl combine the extra virgin olive oil, whole milk, eggs, and vanilla extract. You can do this in the bowl of a stand mixer with a paddle attachment, but I find it easier to mix it by hand (easier cleanup).

Step 3. Add Sugar, Lemon Zest, and Lemon Juice and Combine.

Step 4. Add the Dry Ingredients: Add the baking powder, salt, and flour and combine. Scrape down the sides of the bowl as needed. Do not over stir.

Step 5. Add the Blueberries: Add the blueberries and gently combine with a spoon.

Step 6. Bake: Divide the batter evenly between the two prepared cake pans. Bake at 350°F in the preheated oven for 45-50 minutes, or until a toothpick inserted in the middle comes out clean. The cakes will be golden brown on top when they are done with a slight dome on top.

Allow the cakes to cool.

Step 7: Start the Lemon Curd: Add the egg yolks to a medium bowl.

Step 8. Lemon Mixture: In a medium saucepan combine the lemon zest, fresh lemon juice, granulated sugar, and salt. Bring to a simmer at medium heat.

Step 9. Combine Lemon Mixture and Egg Mixture: While stirring constantly, slowly pour the hot lemon mixture into the egg mixture. Transfer the combined lemon-egg mixture back to the saucepan and cook, stirring constantly for 5-10 minutes until thickened.

Step 10: Strain: Pour the mixture through a fine mesh strainer into a separate bowl to ensure a smooth curd. Allow the curd to fully cool.

Step 11. Make the Mascarpone Frosting: In a large mixing bowl combine the softened mascarpone cheese, softened butter, powdered sugar, and vanilla extract.

Step 12: Start Assembling the Cake: Remove the first cake from the cake tin. Place it right side up on a cake plate or cake stand. Use a bread knife to remove the top domed portion of the cake to create a flat surface.

Tip: Removing the top dome portion of the cake allows the two cake layers to sit flat on each other.

Step 13. Layer the Lemon Curd: Add the lemon curd on top of the cake and spread towards the edges. You can use an offset spatula or a large butter knife to spread the lemon curd.

Step 14: Add the Second Cake Layer: As with the first cake, remove the second cake from the cake tin. Use a bread knife to remove the top dome portion of the cake to create a flat surface.

Invert the cake over the first cake and lemon curd, such that the bottom of the second case is now on the top.

Step 15: Start a Crumb Coat: Add several dollops of mascarpone frosting to the top of the cake. Create a thin layer of frosting over the entire cake. This is called the crumb coat.

Step 16. Refrigerate: Once the cake has a completed crumb coat, refrigerate for 30 minutes to allow the frosting to set. Do not refrigerate the remaining frosting. It should stay in the bowl on the counter to ensure that it stays soft and spreadable.

Step 17: Final Frosting: Remove the cake from the fridge and coat it with the remaining mascarpone frosting with an offset spatula if possible for a smooth finish.