The Absolute Best Lemon Curd Cake Filling Recipe

May 29

When you’re selecting a cake for a special occasion, you have to decide what flavor combinations you want the cake to be. If you’re working with a vanilla, yellow, chocolate, or even red velvet cake, you have tons and tons of options for fillings, frosting, and more. When it comes to vanilla or yellow cake, you have the most options because they’re such neutral flavors. Fudge, berry, pastry cream, caramel, citrus, the list goes on and on.

Today, let’s talk about lemon cake filling. There are several different kinds of lemon fillings you could use between cake layers: a lemony buttercream, lemon white chocolate whipped ganache, a lemony whipped cream, or perhaps the most classic, lemon curd.

Whether you’re using it as a lemon cake filling, a lemon pie filling (lemon meringue pie, anyone?), serving it along scones, filling lemon cupcakes, or topping pound cake or angel food cake with it, your own lemon curd is super versatile and super delicious—lemon lovers won't be able to get enough of it.

Why You’ll Love This Lemon Curd Cake Filling

Bright, punchy flavor: A good lemon curd is absolutely bursting with zesty, lemon flavor. This one is tangy, but with the perfect touch of sweetness to mellow it out a little bit.
Super silky and smooth: The best lemon curd is velvety smooth. The gelatin gives it a hand here and makes it thick and luxe without being gummy.
So versatile: You can use this lemon cake filling to fill layer cakes (duh), cupcakes, tarts, French macarons, or to serve with scones, cakes, shortbread cookies, and more.

Ingredients

350g fresh lemon juice
300g unsalted butter, cubed
300g sugar
200g whole eggs
108g egg yolks
100g more sugar
15g vanilla extract
3g salt
3 gelatin sheets

Instructions

Create a double boiler: Fill a medium saucepan ¼ of the way with water. Place a wide, heat-proof large bowl on top. Bring the water in the saucepan to a simmer over medium-low heat.
Heat the lemon juice and sugar: Add the lemon juice, butter, and 300g of sugar to a separate saucepan. Warm the mixture over medium heat.
Whisk the eggs: Add the whole eggs, egg yolks, vanilla, and salt to the bowl of your stand mixer fitted with the whisk attachment. Add 100g of sugar to the bowl and whisk well.
Bloom the gelatin: Add the gelatin to a small bowl of cold water. Once the gelatin is softened, wring them out and place them on a paper towel.
Combine the lemon mixture and eggs: When the lemon and butter mixture starts to boil, slowly stream a small amount of the hot lemon mixture into the whipped eggs with the mixer running on low speed. Scrape down the sides of the bowl.
Heat the egg mixture: Transfer the egg and lemon mixture into the bowl of your double boiler. Whisk the mixture constantly with a wire whisk until the curd reaches 183-185 degrees F.
Add the gelatin: Add the bloomed gelatin to the bowl of the double boiler. Whisk thoroughly until the gelatin is fully incorporated. Strain the lemon curd through a fine mesh sieve (or a chinois if you have it), then blend with an immersion blender until it’s silky, glossy, and smooth.
Chill the lemon curd: Pour the lemon curd into layer cake pans or shallow bowls and press plastic wrap directly on top of the surface of the lemon curd. Chill the curd thoroughly.

Cake Flavors to Pair With Lemon Cake Filling

Lemon cake fillings go so well with all different sorts of cakes. Because lemon curd is tart, tangy, and a bit sweet, it can hold up well to so many different flavors. If you’re looking for a show-stopping flavor combination, try one of these cakes with your lemon filling:

Classic Vanilla Sponge or White Cake

This traditional favorite lets the lemon cake filling be the star of the show. Top it off with whipped mascarpone or Italian meringue buttercream and you’ve got a delicious upgrade on a soft, buttery classic.

Strawberry Cake

Strawberry and lemon go together so, so well. The sweet berry and bright lemony tang balance perfectly. Add to all of that a light, lemony whipped cream or lemon buttercream? You’ve got a cake that screams “summer.”

Coconut Cake

Coconut and lemon is such a refreshing combination. Frost the outside with a creamy coconut frosting or go classic with a simple vanilla buttercream.

Almond Cake

Nutty and slightly floral, an almond cake is an ideal sweet and sophisticated contrast to a bright, punchy lemon curd filling. Cover the outside with a whipped white chocolate ganache or raspberry whipped mascarpone for a delicious and unexpected cake that feels so special.

Elderflower Cake

Floral and elegant, elderflower and lemon are a gorgeous combination. While elderflower is delicate and refined, lemon adds some oomph. Slather a classic vanilla Italian meringue buttercream all over the outside of the cake and you’ve got the perfect dessert for a summer garden party.

White Chocolate Cake

White chocolate tends to be extremely sweet, but lemon cuts through it so well. Frost the cake with a whipped white chocolate ganache, Italian meringue buttercream, or cream cheese frosting for a real treat.

Lemon Cake

Double lemon is always a good idea. Cover the outside of the lemon cake layers with a lightly lemon frosting, cream cheese frosting, or a classic vanilla Italian meringue buttercream.

Our Best Pro Tips for Making Lemon Cake Filling

Use room temperature eggs: Room temperature eggs will result in a smoother, silkier emulsion.
Make sure you strain the curd: You want the smoothest lemon curd possible, so make sure you don’t skip the straining step. It can remove any accidental cooked egg bits or anything else that will compromise the silkiness of the curd.
Pipe a layer of buttercream: Add a little bit of buttercream around the edge of the cake layer so that the lemon curd stays in the middle of the cake and doesn’t slide out the sides of the cake.

FAQs

Absolutely. The lemon curd works best when it’s fully chilled. Make the lemon curd in advance and store it in an airtight container in the fridge for up to 1 week. Make sure you blend or whisk the lemon curd again before using to make sure it’s as silky smooth as possible.
Yes, you can. If you only have powdered gelatin, you can use that instead of the gelatin sheets. According to The Kitchn, one tablespoon of powdered gelatin equals about 4 sheets of gelatin. Make sure you still bloom the powdered gelatin in water before adding it to the lemon mixture. If you don’t bloom the gelatin ahead of time, you’ll end up with something more like Jell-O than a silky, smooth curd
Yep. Lemon curd doesn’t require the addition of gelatin, but it makes the filling more stable, so we’d definitely recommend it. You’ll need to cook the curd longer and will likely need to add another thickener to your lemon curd to make sure it’s thick enough to act as a filling.
You really do. Bottled juice is convenient, sure, but it doesn’t have even close to the same flavor as freshly squeezed lemon juice. It’s worth the extra effort.
You don’t have to, but it does make a big difference. It’ll make sure that the end result is ultra-smooth, glossy, and gorgeous. The blender will help break up any missed egg bits and make sure everything is completely emulsified.

If you’ve never made your own homemade lemon curd, it’s time to take the plunge. Bright, punchy, and so lemony-fresh, it’s the best lemon cake filling. You won’t be sorry.

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