Keep things fresh and bright with this single layer Lemon Cake with Mascarpone Buttercream. Enhanced with homemade lemon syrup, lemon sugar, and a rich buttercream frosting, this cake is the perfect dessert for small celebrations or for you and a friend!
A moist and fresh single layer lemon mascarpone cake
Run to the store and grab a heap of lemons because this Lemon Cake with Mascarpone Buttercream features a lot of them! Lemons and mascarpone just happen to be a divine combination and I promise you won’t be able to get enough of this vibrant, rich, and moist dessert.
Made with a lemon-infused simple syrup and homemade lemon sugar, every bite of this moist lemon cake recipe sings. Because this is a single layer cake, there’s just enough for a small crowd or just you and a friend. Whip it up when it’s your turn to host brunch or Easter dinner, or double the batch and bring it along to birthdays, baby or wedding showers, holidays, and more.
What is mascarpone buttercream?
A traditional buttercream frosting is made by whipping egg whites and sugar with lots of butter. In this mascarpone buttercream recipe, we’re replacing half of the butter with mascarpone cheese. This soft and acidic Italian cream cheese-like cheese is actually less acidic than regular cream cheese, making it the perfect partner to tart lemon cakes, sandwich cookies, and lemon tarts.
Lemon cake ingredients
- Lemon sugar - Flavoring white granulated sugar with lemon zest is the best way to amp up a simple lemon cake and buttercream.
- Unsalted butter - This lemon cake recipe only requires ½ cup of butter because there’s only one layer. Definitely stock up on more if you turn this into a two or three layer cake (see directions below)!
- Vanilla extract - The warmth from vanilla extract will help tone down the acidity form the citrus.
- Lemon juice - I’m stating the obvious here, but it just isn’t a lemon cake without fresh lemon juice. I can’t emphasize it enough - always use fresh lemon juice!
- Lemon simple syrup - I’m all about simple syrup infusions and this recipe features one of my favorites: lemon simple syrup. Drizzling this homemade syrup over the baked cake will ensure a moist bite and bursts of lemon flavor!
- Mascarpone buttercream - This smooth and creamy buttercream is whipped together with egg whites, white sugar, unsalted butter, and mascarpone cheese.
How to make lemon cake with mascarpone buttercream
Step 1: Make the lemon simple syrup. Heat the water and sugar in a saucepan over medium heat until the sugar has dissolved. Add the lemon slices and let it sit on the heat for 30 seconds. Take the pot off the heat and let the syrup infuse until it cools completely. Drain, transfer the syrup to an airtight container, and leave it in the fridge until you’re ready to use.
Step 2: Make the lemon sugar. Add the sugar and lemon zest to a food processor and blend for 4 minutes.
Step 3: Combine the dry ingredients. Whisk the flour, baking powder, baking soda, and salt in a bowl.
Step 4: Combine the wet ingredients. Beat the butter and sugar together until light and fluffy. Beat in one egg at a time until the wet ingredients are all mixed together well.
Step 5: Finish the cake batter. Add half of the dry mixture as well as the lemon juice and milk to the wet mixture and gently mix. Add the rest of the dry ingredients and mix until just combined.
Step 6: Bake and cool. Pour the batter into a cake pan and bake until a toothpick inserted in the center comes out clean. Let the lemon cake cool completely before you start assembling and decorating.
How to make mascarpone buttercream frosting
Step 1: Heat and whisk the sugar and eggs. In the bowl of a stand mixer, heat the lemon sugar and egg whites over a saucepan of boiling water. Whisk the eggs and sugar until the sugar has dissolved. You’ll know the mixture is ready to be removed from the heat when it reaches 165ºF.
Step 2: Look for soft peaks. Attach the bowl to the stand mixer and mix on low speed. Gradually increase the speed until soft peaks form and has cooled.
Step 3: Add the butter and cheese. Switch to the paddle attachment and add a tablespoon of butter and mascarpone to the mix at a time. The mascarpone buttercream is ready with the mixture is smooth and glossy.
Assembly and decorating
Now that the cake and buttercream are ready, it’s time to assemble and decorate!
Step 1: Drizzle the lemon syrup on top. Use a toothpick to poke small holes all over the top of the cake. Drizzle the lemon simple syrup over the top so it soaks right into the cake.
Step 2: Add the icing. Spread the mascarpone buttercream over the top of the cake using an offset spatula or spoon. Feel free to spread it on the sides as well!
Step 3: Decorate and enjoy! Garnish the cake with fresh blueberries, food-safe edible flowers, candied lemons, whipped cream, and/or greenery. Slice it up and dig in!
Tips to make the best lemon cake
- If you don’t want to make lemon sugar, just add the white sugar and lemon zest to the cake batter and buttercream separately.
- Don’t even bother with bottled lemon juice! The flavors just can’t compete with the fresh stuff.
- Wanna keep it simple? Forget the buttercream and drizzle a homemade vanilla glaze over the cake instead.
- Every single piece (I’m talking lemon syrup, lemon sugar, lemon cake, and mascarpone buttercream) of this recipe can be prepared a few days ahead of time. Just store each element in plastic or airtight containers and keep them in the fridge until it’s time to assemble.
Frequently asked questions
What can you substitute for mascarpone?
Regular cream cheese works in place of the mascarpone, but the finished buttercream will be slightly more tangy and acidic.
What pan should you use to bake lemon cake?
A 6-inch cake pan is perfect if you’re looking for a simple presentation and to serve a small crowd. Alternatively, you can turn this recipe into a lemon loaf by baking it in a loaf pan or use a small bundt pan when you’re craving lemon bundt cake. For a shorter cake, you can bake the batter in an 8-inch cake pan.
Different cake pans will warrant different baking times. The bigger your pan, the less time it will take to bake.
Can you make this a double or triple layer cake?
Absolutely! Simply double or triple the recipe if you need to serve more people or make the cake grander. Bake the batter in 6-inch or 8-inch round cake pans or bundt pans.
How long does it last?
The cake and individual slices will store well for 4 days in the fridge. Just wrap the cake in plastic or keep the slices in airtight containers.
More fresh lemony desserts
- Dairy Free Mini Lemon Cakes
- Lemon Poppyseed Cake
- Lemon and Mascarpone Tart
- Old Fashioned Lemon Poppyseed Doughnuts
Lemon Cake with Mascarpone Buttercream
- Stand Mixer with Paddle and Whisk Attachment
- 6 inch Cake Pan for a tall Single Layer Cake
- 8 inch Cake Pan for a shorter Single Layer Cake
- Parchment Paper
- Cooling Rack
Lemon Simple Syrup
- ½ Cup (125 g) Water
- ½ Cup (100 g) Granulated Sugar
- 1 Lemon, sliced into thin circles
- ¾ Cup (150 g) Sugar
- 4 Lemons, zested
- 1 ¼ cups (155 g) All-Purpose Flour
- 1 teaspoon Baking Powder
- ⅛ teaspoon Baking Soda
- ¼ teaspoon Salt
- ½ cup (114 g) Unsalted Butter, room temperature
- ¾ cups (150 g) Lemon Sugar
- ¼ teaspoon Vanilla Extract
- 2 Eggs, large
- ⅓ cup + 1 Tbsp (100 g) Milk
- ¼ cup (61 g) Lemon Juice
- 3 Egg Whites
- 1 Cup (200 g) Granulated Sugar
- ⅔ Cup (150 g) Unsalted Butter, Room Temperature
- ⅔ Cup (150 g) Mascarpone, Room Temperature
- Food Safe Organic Florals
Lemon Simple Syrup
- Pour your measured water and sugar into a saucepan and heat on medium
- Cook, stirring the mixture, until your sugar has completely dissolved.
- Add lemon slices and continue heating for 30 seconds before removing from heat
- Allow syrup to infuse for half and hour as the simple syrup cools completely
- Strain syrup into airtight container and store in the fridge or until you're ready to use.
- Place lemon zest and sugar in a food processor and process for 4 minutes. Alternatively, use clean fingers and rub the zest and the sugar together so that the oils of the lemon zest start to incorporating into the sugar granules. Set aside until you start the process of making the cake.
- Preheat your oven to 350 degrees Fahrenheit.
- Combine all your dry ingredients - flour, baking powder, baking soda and salt in a medium sized bowl, give it a whisk and set aside.
- Add the butter and sugar into a large bowl and beat together until light in color and fluffy, about 3-5 minutes.
- Add the eggs one at a time, then scrape the bowl making sure ingredients are mixed well.
- Add ½ the dry ingredients, then add the combined lemon juice and milk to the batter. Finally add the last half of the dry ingredients and mix until just combined.
- Pour batter into a greased 6-inch cake pan and bake for 28-35 minutes. For a shorter cake, you can bake the batter in an 8-inch cake pan for 25-28 minutes. Make sure to check that the cake is fully baked with a toothpick before removing from the oven and allowing to cool completely before assembling.
- Add your lemon sugar and egg whites in the bowl of a stand mixer and place over a saucepan of boiling water. Make sure that your bowl is not touching the hot water! Your goal is to simply whisk the egg whites and sugar together over a gentle heat until the sugar has completely dissolved, then attach your bowl back to the standing mixer. The temperature should read 165 F before it's ready to be removed from the heat.
- Whisk mixture starting at a low speed and gradually increase until soft peaks form and the mixture has cooled. Switch to using your paddle attachment, then start adding your butter and mascarpone bit by bit.
- When you’ve reached the point where the buttercream is glossy and smooth, stop the mixer and set aside for assembling.
- Once you've prepared all the cake components - it's time to assemble your cake! First off, poke many small holes into your lemon cake with a toothpick before drizzling some of your lemon simple syrup over the top of the cake. This ensures that it is incredibly moist and bursting with lemon flavor!
- Add as much of your mascarpone buttercream on top of the cake and spread evenly. Utilizing a spoon or an offset spatula, create swirls and swoops to your liking into the buttercream! I used a small spoon to create the swirls you see below.
- Add the decoration of your liking on top! I added a couple different layers of toppings, starting with some blueberries, then organic flowers and greenery to add for a pleasing aesthetic.