Soft, moist and tart lemon curd cake with a delicious lemon cake batter made with lemon zest, and an easy creamy lemon curd cake filling. A 1x batch yields 1 6" three-layer cake, and a 2x batch yields 1 8" three-layer cake cut out with cake rings using the Cut and Stack Method. Or choose a different pan size by visiting my recommended cake pan chart.
Servings 8servings
Prep Time 30 minutesmins
Cook Time 24 minutesmins
Cake Layering Time 25 minutesmins
Ingredients
Dry Ingredients
200 grams (1 ½cups)All-Purpose FlourI use Gold Medal
Preheat oven to 325 degrees. Line a 1" tall ¼ sheet pan with parchment paper, then lightly spray the bottom (on top of the parchment) and sides of the pan with nonstick cooking spray.
Zest the 4 lemons, reserving zest from 2 lemons for the cake, and zest from 2 lemons for the lemon curd filling. Juice the lemons to make ¼ cup lemon juice for the cake, and ½ cup for the lemon curd. If you are short any lemon juice, you can fill in with juice from another 1-2 lemons, or add bottled lemon juice to get the necessary quantities.
Using a sifter or fine mesh strainer, sift the Dry Ingredients into a large bowl, then whisk until well blended.
Combine Wet Ingredients in a separate large bowl and whisk until smooth and well-blended.
2 large Eggs, ¾ cup Buttermilk, ¼ cup + 3 Tablespoons Vegetable Oil, 1 ½ teaspoons Vanilla Extract, 2 teaspoons Pure Lemon Extract, Zest from 2 large lemons
Pour the Wet Ingredients over the Dry Ingredients, then immediately (before stirring) add in the lemon juice. Whisk everything together--the lemon juice will bubble slightly as it reacts with the wet and dry ingredients. Pour the melted Butter into the batter and whisk until smooth, uniform and lump-free.
Pour the lemon curd cake batter into the prepared ¼ sheet pan and smooth out the batter until even (an offset icing spatula works well for this). Bake the cake soon after spreading the batter into the pan.
Bake on the middle or top rack (avoid bottom rack) of the preheated 325-degree oven for 22-26 minutes, or until a toothpick or paring knife comes out clean (watch closely towards the end of baking). A couple of moist crumbs on your knife are fine, but they shouldn't look wet. Some ovens may require a longer baking time, and 2x batches may take a few more minutes in the oven.
The delicate cake will be easiest to layer from cold or frozen--allow the cake to cool, then wrap the cake in the pan thoroughly in plastic wrap. Freeze the cake in the pan for at least 2 hours or up to 2 weeks ahead of time (brush the cake with simple syrup if freezing for more than a couple of days--see Note #2).
Make the Thick Lemon Curd Filling
For best results, make the lemon curd a day before using (or while baking the cake). Whisk the sugar and instant clearjel well together. Set aside.
Whisk the lemon juice and egg yolks together in a saucepan. Cook over medium-low heat, whisking frequently, just until it comes to a boil.
½ cup Fresh lemon juice, 4 egg yolks
Remove from heat and add the 2 ounces room temperature butter to the lemon mixture, stirring until the butter is melted and well blended. Pour the hot lemon curd base through a fine mesh strainer to remove any lumps or egg strands.
½ stick (2 ounces) salted butter
Slowly whisk in the instant clearjel mixture to the lemon curd, a little at a time, until the instant clearjel mixture is fully incorporated and dissolved. Stir in the lemon zest. The lemon curd will thicken, but will continue to thicken as it cools. This lemon curd is thicker and has a more textured appearance than traditional lemon curd due to the starch that thickens it, but it has a smooth mouthfeel.
Zest from 2 large lemons
Allow the lemon curd to cool and get cold in the fridge until you're ready to use it, ideally for two hours or overnight. Stir before using.
The easiest way to layer this lemon curd is to layer it from frozen the day before you plan to serve it. If serving the cake the same day you are layering it, use refrigerated cake layers instead of frozen. Cut the cake layers with cake rings as described in How to Bake and Layer Cakes Like a Pro. Use the remaining cake scraps to make cake truffles, if desired.
When filling this cake with lemon curd filling, you’ll want to start by spreading a very thin layer of vanilla buttercream on each cake layer before filling the cake.
Next, pipe a ring of prepared house vanilla buttercream around the edge before spooning in your lemon filling. Pipe the buttercream 2-3 rings high to ensure no filling escapes. Spoon half of your lemon curd into the ring, and make sure it is under the height of your buttercream ring. Top the lemon curd with the additional cake layer (pan-side up).
Some buttercream will push over the edge when topped with the cake layers, which is fine–just use your spatulato smooth it against the side of the cake to seal it in. (To be extra cautious with filled cakes, I like to let them set up in the freezer for 10 minutes after filling them but before adding a crumb coat of icing.)
I recommend frosting a thin crumb coat of buttercream on the outside of the cake ,which will catch all the crumby edges, then allow it to set up in the freezer for about 10 minutes until the buttercream is firm, before adding the final coat of vanilla buttercream.
You can let the cake set up in the fridge, but remove it from the fridge 2-3 hours before serving so it can come back to room temperature (avoid warm temperatures). This lemon curd cake has the best texture at room temperature. Enjoy!
Notes
Notes for 2x batches (some of these won’t apply if you are using the grams measurements): 3 tsp= 1 Tbsp 4 tablespoon = ¼ cup
Instant Pudding Mix and Instant Clearjel stabilize the batter and make a moister cake with a softer crumb. Instant Pudding contains Instant Clearjel (modified cornstarch) as the 2nd ingredient which is why they work similarly with delicious results. Make sure whichever you use is labeled as INSTANT--cook-type and original clearjel do not work the same as Instant Clearjel.
Simple Syrup is optional, but I use it to seal in the moisture for cakes that will be refrigerated or frozen. While the cake cools, make a simple syrup by combining 1 tablespoon water and 1 tablespoon sugar in a small microwave-safe bowl. Microwave until the sugar is dissolved after whisking, about 20-30 seconds. You will only need half of this on a 1x batch of cake. You can also make a larger batch of this (1 part sugar to 1 part water) and keep it in the fridge if you're doing a lot of cake baking.