Soft, zesty, and bursting with sunshine, these Lemon Poppyseed Slab Cakes are everything you love about spring baked into one beautiful, sliceable dessert.

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About This Recipe

If you love lemon desserts, this one is going to obsess you. It starts with an ultra-moist lemon poppyseed loaf cake that’s soaked in a bright lemon syrup, giving it that irresistible melt-in-your-mouth texture. The poppyseeds add just the right amount of subtle crunch, making every bite more interesting.

But what really makes this recipe special is the way it’s served. Instead of slicing and serving plain, each piece is topped with a cloud of mascarpone whipped cream and a glossy spoonful of lemon curd. The result? A perfect balance of soft, creamy, and tangy in every single bite.

This cake style has been all over Pinterest lately, and for good reason. It’s elegant, aesthetic, and incredibly practical. Each slice is individually portioned and beautifully decorated, making it perfect for brunch tables, spring gatherings, or summer parties. Plus, it guarantees that everyone gets the full experience—cake, cream, and curd—all in one serving.

What You Need To Make This Recipe

For the Lemon Poppyseed Loaf Cake:

Unsalted butter – Adds richness and keeps the cake soft and moist. You can substitute with neutral oil for an even softer texture, but you’ll lose a bit of buttery flavor.
Granulated sugar
Lemon zest – The key to that bold, fresh lemon flavor. Don’t skip this, it’s where most of the flavor comes from.
Eggs – Provide structure and help the cake rise. Make sure they’re room temperature for a smooth batter.
Full-fat yogurt – Adds moisture and a slight tang, making the cake extra soft. Can be substituted with sour cream.
Lemon juice – Enhances the citrus flavor and balances the sweetness.
All-purpose flour
Baking powder – Helps the cake rise and stay light.
Poppyseeds – Add a subtle crunch and that classic lemon-poppyseed texture.

For the Lemon Syrup:

Granulated sugar – Sweetens the syrup and helps it soak into the cake.
Lemon juice – Soaks into the cake to intensify the lemon flavor and keep it ultra moist.

For the Mascarpone Whipped Cream Frosting:

Mascarpone – Makes the frosting rich, creamy, and more stable than regular whipped cream. It can be swapped with brick-style cream cheese for a slightly tangier flavor.
Heavy cream – Whips up to create a light, airy texture. Make sure your cream is fully chilled and has a fat percentage of 35% or higher.
Vanilla extract
Powdered sugar – Sweetens and stabilizes the whipped cream. Adjust to taste.

For the Lemon Curd:

Egg + egg yolks – Thicken the curd and give it a rich, silky texture.
Granulated sugar.
Cornstarch – Helps stabilize and thicken the curd so it sets nicely.
Lemon juice
Lemon zest
Unsalted butter – Adds richness and gives the curd a smooth, glossy finish.

Equipment For This Recipe

Pro Tips

Rub the lemon zest into the sugar before mixing—it releases oils and boosts flavor.
Don’t overmix the batter once the flour is added, or the cake can turn dense.
Soak the cake while warm so the syrup absorbs fully and keeps it extra moist.
Use cold ingredients for the frosting to get stable, fluffy peaks.
Cook lemon curd on very low heat to avoid scrambling the eggs.
Chill the curd fully before assembling—it thickens and becomes glossy.
Pipe generously but not excessively—you want balance, not overload.

How To Store Lemon Poppyseed Slab Cakes

Cake (without toppings): Store in an airtight container at room temperature for 1–2 days or refrigerate for up to 4 days.

Lemon curd: Keep refrigerated in an airtight container for up to 1 week.

Frosting: Store in the fridge and use within 2–3 days. Beat with an electric mixer until fluffy before using.

Assembled slices: Best enjoyed fresh, but can be refrigerated for up to 1-2 days.

FAQs

Can I make this ahead of time?

Yes! The cake and lemon curd can be made a day in advance. Assemble just before serving for the best texture.

Can I skip the mascarpone?

You can use regular whipped cream, but mascarpone adds richness and stability. Plus, the flavor works so well with the tartness of the cake and lemon curd.

Why is my lemon curd too thin?

It likely needs more cooking time or more chilling time to fully set.

Can I use store-bought lemon curd?

Yes, but homemade gives a fresher, brighter flavor.

Can I make this into a full cake instead of slices?

You can, but the slab-style slices are what make this recipe unique and perfect for serving.

These Lemon Poppyseed Slab Cakes are the definition of a feel-good dessert—bright, fresh, and effortlessly pretty. Whether you’re hosting a brunch or just craving something lemony and special, this recipe brings both flavor and aesthetic to the table.

If you’re looking for more spring bakes, then you have to try my Lemon Blueberry Loaf Cake, Blueberry Cream Cheese Danish Buns, Strawberry Gallete, Lemon Blueberry Cake with Cream Cheese Frosting, and my No-Bake Lemon Cheesecake!

Check out my YouTube Channel for more delicious recipe tutorials! Made one of my recipes? Tag me on Instagram, I would love to see your creations!

Lemon Poppyseed Slab Cakes

Soft, zesty, and bursting with sunshine, these Lemon Poppyseed Slab Cakes are everything you love about spring baked into one beautiful, sliceable dessert.

Print Recipe Pin Recipe

Prep Time 35

Cook Time 45

Cooling time 1

Total Time 2 20

Course Dessert

Cuisine American

Servings 10

Calories 420 kcal

Equipment

1 Large bowl
1 Medium sized bowls
2 Small bowls
2 Whisks
2 Spatulas
Loaf pan (8.5×4.5 inch) greased and lined with parchment paper
1 Skewer
1 Electric hand/stand mixer to make frosting
Kichen scale or measuring cups
Measuring spoons
1 Piping bag

Ingredients

For the Lemon Poppyseed Loaf Cake

113 g unsalted butter (1/2 cup) melted & cooled
150 g granulated sugar (3/4 cup)
Zest of 2 lemons
2 large eggs room temp
120 g full-fat yogurt (1/2 cup)
60 ml lemon juice (1/4 cup)
180 g all-purpose flour (1 1/2 cups)
2 tsp baking powder
2 tbsp poppyseeds

For the Lemon Syrup

50 g granulated sugar (1/4 cup)
3 tbsp lemon juice

For the Mascarpone Whipped Cream Frosting

50 g mascarpone (1/4 cup) cold
120 ml heavy cream (1/2 cup) cold
1/2 tsp vanilla extract
4 tbsp powdered sugar or to taste

For the Lemon Curd

1 egg
2 egg yolks
100 g granulated sugar (1/2 cup)
3/4 tbsp cornstarch
Juice of 2 lemons
Zest of 1 lemon
40 g unsalted butter (~ 3 tbsp)

Instructions

Make the Lemon Poppyseed Loaf Cake

Preheat oven to 160°C/320°F. Grease and line a loaf pan.
In a bowl, whisk melted butter, sugar, and lemon zest. Add eggs and mix.
Mix in yogurt and lemon juice. Sift in flour, baking powder, and salt. Add poppyseeds and mix until combined.
Pour into pan and bake for 40–45 minutes, or until a toothpick comes out clean. Cover with foil if the top is browning too fast.

Make the Lemon Syrup

Mix sugar and lemon juice, then microwave for ~30 seconds until dissolved.
Poke holes in the warm cake and pour syrup over. Let cool completely.
Loaf cake generally take longer to cool down completely compared to regular cake layer, so the laf cake can be made a day ahead.

Make the Mascarpone Whipped Cream

Use an electric hand/stand mixer to whip heavy cream with powdered sugar until stiff peaks form, takes around 4-6 mins depending on the speed of your mixer.
In another bowl, beat mascarpone until smooth. Fold into whipped cream in batches.
Transfer to a piping bag and refrigerate.

Make the Lemon Curd

Whisk egg, yolks, and sugar until fluffy. Add cornstarch, lemon juice, and zest.
Cook on very low heat, whisking constantly, until thick (5–7 minutes).
Remove from heat, add butter in batches, then strain using a seieve to remove the lemon zest and any small lumps in the lemon curd.
Chill for at least 1 hour before using on the cake. Lemon curd can be made upto a4 days in advance and stored in the refrigerator.