Creamy and tart, lemon cake filling takes minutes to make. Brighten cakes and desserts with sunny homemade lemon custard. 

Image of lemon cake filling in a small jar with a white spoon. A lemon is pictured in the background.

Do you love the tartness of lemon and the creaminess of pudding? Do you enjoy bright and light desserts? Well, who doesn’t, right? Lemon cake filling, made from scratch in your own kitchen, will be appreciated by everyone. It’s versatile enough to use in a lot of different desserts or to serve in a dessert bowl, without any embellishment.

About this lemon cake filling:

While making lemon cake filling yourself may seem daunting, it’s really not difficult at all. You’ll be able to make this custard-like filling in 15 minutes. You won’t need any special equipment and you won’t need to learn any fancy cooking techniques.

Lemon filling is so good, you’ll want to leave a fair amount of it in the pan for the cook’s enjoyment. Hey, I’m talking about you! Don’t deny the urge to sample what the pan has to offer. That’s your bonus.

Image of pale yellow lemon cake filling in a small jar with a white spoon next to it.

How do you make lemon filling from scratch?

Lemon cake filling is a one-pan recipe.

The ingredients are basic:

  • lemon juice
  • butter
  • egg yolk
  • sugar
  • cornstarch
  • salt
  • water

You’ll mix the dry ingredients in the pan, blend in the egg yolks, whisk in the water and cook, stirring constantly, until the mixture comes to a boil and thickens. Stir in the butter and lemon juice, adding a bit of lemon zest, too, and you’re done! It’s so easy. 

What’s the difference between lemon filling and lemon curd?

Lemon filling or custard is usually thickened with cornstarch and can be cooked in a regular saucepan. Lemon curd is richer, with more egg yolks and lots of butter, no water or cornstarch, and is usually made in a double boiler. They can be used pretty interchangeably.

Overhead image of lemon cake filling in a small jar.

What flavors of cake go well with lemon cake filling?

Lemon cake filling goes well with white cake, yellow cake, or lemon cake. Try it layered in a trifle with pound cake, angel food cake, or lady fingers. 

Image of cake filling made with lemons.

How to use this lemon filling:

Because this lemon filling recipe is very simple, there aren’t a lot of ways to make it uniquely your own creation. However, there are lots of different ways to use it.

Of course, you can use lemon filling as a filling in a layer cake.  Or serve it in a bowl with a dollop of whipped cream as a dessert on its own. Make lemon custard tarts with pre-baked pastry shells or mini phyllo cups. Layer it in a trifle with angel food cake or pound cake, with fresh strawberries. Or make regular cupcakes extra special with a hidden jewel of lemon filling. 

Storage Tips

Lemon cake filling will keep in the fridge up to a week, tightly covered.

More Lemons

Okay, I realize “lemon” can have a double meaning, as in “this recipe is a real lemon” but that’s not true of these recipes. You’ll love these lemons: 


Image of pale yellow lemon cake filling in a small jar with a white spoon next to it.

Lemon Cake Filling

Yield: 1 1/2 cups
Prep Time: 10 minutes
Cook Time: 10 minutes
Additional Time: 1 hour
Total Time: 1 hour 20 minutes

Creamy and tart, lemon cake filling takes minutes to make. Brighten cakes and desserts with sunny homemade lemon custard. 


  • 1/2 cup sugar
  • ¼ cup cornstarch
  • 1/4 teaspoon salt
  • 2 egg yolks
  • 3/4 cup water
  • 2 tablespoons unsalted butter, softened
  • ⅓ cup freshly squeezed lemon juice
  • 1 teaspoon lemon zest


  1. Have all your ingredients ready before you begin. Mix sugar, cornstarch and salt in a small saucepan. Add egg yolks and mix until egg yolks are completely mixed with dry ingredients. Whisk in water until mixture is smooth.
  2. Cook over medium low heat until just boiling. Mixture will be quite thick. Immediately remove from heat and stir in butter. Gradually whisk in lemon juice until smooth. Stir in zest. 
  3. Pour into a bowl and cover the surface of the filling with plastic wrap. Refrigerate until firm, about 1 hour.

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Nutrition Information:
Yield: 6 Serving Size: 1/4 cup
Amount Per Serving: Calories: 139Total Fat: 5gSaturated Fat: 3gTrans Fat: 0gUnsaturated Fat: 2gCholesterol: 72mgSodium: 96mgCarbohydrates: 23gFiber: 0gSugar: 17gProtein: 1g sometimes provides nutritional information, but these figures should be considered estimates, as they are not calculated by a registered dietitian. Please consult a medical professional for any specific nutrition, diet, or allergy advice.

Did you make this recipe?

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Verdict: Love this easy cake filling!
Husband’s take: Ben loves white cake with chocolate frosting, but the guy doesn’t complain if I’m making cake.
Changes I would make: None are necessary!
Difficulty: Easy!