This Lemon Poppy Layer Cake is a perfected spin on the classic. An extra-silky Swiss meringue cream cheese buttercream tops fluffy lemon layers of cake specked with poppy seeds in a winning combination.
Lemon is a great spring and summer treat, but everyone always goes for a lemon poppy seed muffin. And yes, I agree, it’s a great bald cupcake, but why not have a whole lemon poppy seed cake too? And obviously that needs to be a layer cake because I want all the cream cheese icing I can manage!
Key Ingredients
What goes into this amazing lemon cake? There are two main components here: the lemon poppy layers and a cream cheese buttercream. So let’s break down the key ingredients!
Lemon Poppy Cake
- Cake flour. I love to use cake flour in my layer cakes because it makes for a light and soft cake. Cake flour is finer and has less protein/gluten in it for a great cake texture.
- Unsalted butter and neutral oil. My cake recipes often include both butter and oil for the best mix of butter flavor with the moisture from the canola or vegetable oil.
- Fresh lemon. Use fresh lemon zest and lemon juice, skip the pre-bottled juices.
- Whole milk and sour cream. These both bring richness to the cake. I’ve tried this recipe with all lemon juice and no milk and it was a weird, dry mess. The milk is needed!
- Poppy seeds. Poppy seeds can be found in the spice aisle. These are totally optional, if you aren’t a fan of them, feel free to leave them out!
Swiss Meringue Cream Cheese Icing
- Egg whites. The base of our icing is an egg white meringue, which makes for a super silky icing. You can use carton egg whites, or separate your own eggs, and use the yolks for something else (like this lemon curd tart).
- Unsalted butter. There’s a really high ratio of butter and cream cheese to sugar as compared to a classic American style icing. This is why this buttercream is so buttery and smooth and not too sweet.
- Cream cheese. Use a cheaper, store-brand cream cheese for this recipe. A creamier name-brand option is also wetter and may cause splitting.
Making Dehydrated Lemon Slices
If you want to decorate you cake with the same dehydrated lemon slices as I have, slice a lemon into 1/4″ thick rounds using a sharp knife. Place on a parchment lined baking sheet and bake at 200°F (95°C) for 3-4 hours, turning halfway.
Making a Lemon Layer Cake
I make this cake using what is called the creaming method. So named because we will begin by creaming the butter and sugar until light and fluffy to make a great fluffy cake! It’s how a make nearly all my cakes.
A few tips for a fantastic cake:
Cream the butter and sugar. Really spend the time to whip the butter and sugar well, 5-7 minutes, until it’s very light in color and airy. This is the base of our case for being light and airy too! We are also going to add the zest into this mix to really release all the flavor from the zest.
Alternate dry and wet ingredients. To avoid over-mixing the flour, or having the batter split, I always alternate adding my dry ingredients and the milk. Flour – milk – flour – milk – flour.
Add the poppies last. Avoid grey batter by adding the poppy seeds at the very end and stirring gently.
Tap the cake tins. Give the cake pans a couple of quick taps on the counter after filling to eliminate any large air pockets.
Tips for Even Cake Layers
The bane of every bakers existence is domed cake layers when you want a stacked cake! Here’s a few tips for a flatter cake layer. (I go through all the steps in my level cake post too!)
- Even distribution. Divide the cake batter evenly between each cake tin by either weighing or using an ice cream scoop. Smooth the batter with an offset spatula before baking.
- Bake using cake strips or a DIY version. Using damp cake strips around the outside of cake tins will insulate the edges so they bake more slowly. Domed cakes happen when the edges set while the center keep rising. You can make a DIY version by cutting an old towel into strips and securing with a metal binder clip.
- Trim to height. I will still trim the cakes using a very long serrated knife and a cake turntable. I begin by tracing a level line where I want to cut around the edge with the knife, then slowly bringing the knife into the center of the cake while revolving on the turntable.
- Cold is easier. Cold cake layers are easier to trim than fresh from the oven. If you plan to cut and fill in the same day as baking, pop the layers in the fridge for a few minutes before trimming.
Making Cream Cheese Icing
Because this is a Swiss meringue icing, there are a few extra steps to making a traditional American buttercream with just powdered sugar and butter. But, there is a good reason for these extra steps! When you try how smooth, buttery and the right balance of sweetness, you will never go back!
I go into an in-depth description of the process in my post on Swiss meringue buttercream, but this recipe varies slightly by using cream cheese in addition to the butter for that subtle tangy flavor.
Begin by making a Swiss meringue with egg whites and sugar heated to 165°F (75°C) and whipping until shiny, fluffy and cooled.
Next add softened butter and cream cheese, tablespoons at a time, while still whipping on high. Please do not worry if the mixture looks curdled while you are adding the butter. This is totally normal until the fat in the butter emulsifies. It can sometimes take up to 5-10 minutes for the butter to blend in, so keep whipping.
Finally, add the flavorings. You are now ready to ice your cake! Stack and ice your even cake layers as desired.
Frequently Asked Questions
You can make your own DIY cake flour by swapping 3 tablespoons of flour with cornstarch.
If your butter or cream cheese has gotten warm, you may notice the icing is a little runny. Leave it in the fridge for 10 minutes at a time and retest until you get the consistency desired.
If the butter or cream cheese is too cold, the icing may look a little clumpy. Allow it to sit at room temperature for 10 minutes at a time, and recheck until you have the ideal consistency.
It’s completely normal for the meringue to look a little curdled when you begin to add the butter. Continue whipping on high and you will see it come together in 5-10 minutes – I promise!
Store this cake in an airtight container in the fridge for up to 3 days. The icing is best when allowed to come back to room temperature before enjoying.
Lemon Poppy Layer Cake
Equipment
- 3 6" cake tins
- Digital thermometer
Ingredients
Lemon Cake
- 210 g cake flour
- 1 ¼ teaspoons baking powder
- ¼ teaspoon baking soda
- ½ teaspoon fine kosher salt
- 100 g unsalted butter room temperature
- 225 g granulated sugar
- 2 tablespoons fresh lemon zest
- ¼ cup canola or vegetable oil
- 2 eggs room temperature
- 1 tablespoon vanilla extract
- ¼ cup + 2 tablespoons whole milk room temperature
- 2 tablespoons fresh lemon juice room temperature
- 56 g sour cream room temperature
- 2 tablespoons poppy seeds
Cream Cheese Icing
- ½ cup egg whites room temperature
- 250 g granulated sugar
- 300 g unsalted butter softened, cubed
- 227 g cream cheese* softened, cubed
- 2 teaspoons vanilla extract
- 1 teaspoon fine kosher salt
Instructions
- Lemon poppy cake. Preheat oven to 350°F (175°C). Grease and flour 3 – 6" cake tins. Line the bottoms with parchment paper.
- Sift together cake flour, baking powder, baking soda and salt in a bowl. Set aside.210 g cake flour, 1 1/4 teaspoons baking powder, 1/4 teaspoon baking soda, 1/2 teaspoon fine kosher salt
- In the bowl of a stand mixer fitted with paddle attachment, or in a large bowl with a hand mixer, whip together butter, sugar and lemon zest until light and fluffy, about 5-7 minutes. Scrape down sides of bowl as needed. Add in oil and mix well.100 g unsalted butter, 225 g granulated sugar, 2 tablespoons fresh lemon zest, 1/4 cup canola or vegetable oil
- Add eggs in one at a time with mixer on low. Add vanilla extract.2 eggs, 1 tablespoon vanilla extract
- Alternate between adding the flour and milk, add 1/3 of the flour mixture on low. Add 1/2 of the milk. Continue until all ingredients are combined, scraping down sides of bowl as needed.1/4 cup + 2 tablespoons whole milk
- Stir in lemon juice and sour cream. Then add poppy seeds. Divide batter evenly between prepared pans. Tap a few times on the counter to release any air bubbles. Bake for 24-27 minutes until cake springs back to the touch and a toothpick comes out clean. Allow to cool enough to handle before removing cakes from tins and onto cooling rack. Cool completely before stacking.2 tablespoons fresh lemon juice, 2 tablespoons poppy seeds, 56 g sour cream
- Cream cheese icing. Place egg whites and granulated sugar in a heat-proof bowl, or in the bowl of a stand-mixer. Place bowl over a pot of simmer water, making sure the bottom of the bowl does not touch the water. Continuously stir with a whisk until egg whites reach 165°F (75°C).1/2 cup egg whites, 250 g granulated sugar
- Remove bowl from pot and begin to whip the egg whites on high until mixture cools and stiff meringue forms with glossy, shiny peaks; 5-10 minutes. Begin adding butter and cream cheese, one cube at a time, and continue whipping until smooth buttercream forms; 5-10 minutes.300 g unsalted butter, 227 g cream cheese*
- Add vanilla and salt.2 teaspoons vanilla extract, 1 teaspoon fine kosher salt
- Assembly. When cakes are cool, trim top of layers to even if desired. Generously top each layer with cream cheese buttercream, then cover sides and top of cake. Smooth as desired.
Notes
- *Use a store-brand, not a name-brand cream cheese like Philadelphia. Store-brand cream cheese is less creamy/wet than the name brand options are will avoid issues with splitting.
- Poppy seeds can be omitted if desired
- Store cake in an airtight container for up to 3 days in the fridge.
- Baked cake layers can be wrapped tightly in plastic wrap and frozen for up to 3 months.
Disclaimers
•We use Diamond Crystal fine kosher salt in all our testing, if you are using a table / iodized salt, you may want to reduce the salt by half.
• We test all recipes using the metric weights shown, we cannot guarantee outcomes when switching to US measurements.
Absolutely loved the cake but couldn’t get the buttercream to come together for anything. It was going fine before I added the cream cheese. Then it split slightly and got very thin. Chilled it, a little then it split when beat again. Used similar steps to troubleshoot as I would a SMBC – but it only seemed to get worse. Flavor is great but it’s completely off. Any tips? Seems even more finicky with the addition of the cream cheese.
Hi Katie, thank you for you comment, I’m so glad you enjoyed the cake, but I’m so sorry the buttercream didn’t work out correctly! Sometimes certain brands of cream cheese can be creamier (or wetter) than others and may cause splitting. I appreciate you helping us to realize a disclaimer and recommendations are necessary to avoid failures for others!