This lemon poke cake is made with a soft, moist lemon cake base, a rich lemon curd filling, and a fluffy lemon mascarpone whipped cream frosting.
By using both butter and oil in the batter, the cake stays incredibly tender and stays moist for days (and, of course, because it's filled with lemon curd).
Instead of using instant pudding mix or sweetened condensed milk, I thin out real lemon curd with a splash of milk so it seeps straight into the cake.
To finish it off, I top everything with a light lemon mascarpone whipped cream that isn't overly sweet. It's simple, bright, and perfect for making ahead.
For more lemon desserts, check out my lemon crinkle cookies, lemon pound cake, and lemon curd cookies.
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Why this recipe works
- Real lemon curd center: Thinning out lemon curd with a splash of milk lets it soak deep into the cake, giving you real citrus flavor in every bite instead of a fake, artificial pudding mix taste.
- The butter and oil trick: Butter gives the cake an incredibly rich flavor, while vegetable oil keeps the crumb soft and moist for days, even after chilling in the fridge.
- Light mascarpone frosting: Folding fresh lemon zest into mascarpone whipped cream creates a fluffy, rich topping that isn't heavy or sickeningly sweet.
- Simple sheet pan cake: Everything bakes up in a standard 9x13 pan, making it ideal for prepping ahead of time and serving a crowd.
Ingredients
Full measurements are located in the recipe card at the bottom of the page.
For the Lemon Cake
Unsalted Butter: Softened to room temperature for classic rich bakery flavor.
Vegetable Oil: Keeps the cake structure soft and moist for days in the fridge.
Granulated Sugar: Sweetens the batter and tones down the sour lemon notes.
Eggs: 3 large room-temperature eggs so they mix smoothly into the batter.
Fresh Lemon Juice & Zest: Fresh lemon makes a huge difference here! I recommend zesting the lemons before squeezing out the juice.
All-Purpose Flour: Standard plain flour works great here, though cake flour is a great swap too.
Baking Powder & Baking Soda: Gives the cake its fluffy rise. Check that both are fresh and active!
Sour Cream & Buttermilk: Keeps the crumb rich and tender. Homemade buttermilk works fine too.
Vanilla Extract & Kosher Salt: Rounds out all the flavors and balances the sweetness.
For the Lemon Curd Filling
Lemon Curd: Store-bought or homemade both work great.
Milk: Just a splash to loosen up the curd so it flows straight into the poked holes.
For the Lemon Mascarpone Frosting
Mascarpone Cheese: Let it sit at room temperature for 30 minutes so it folds smoothly into the cream without clumping.
Heavy Whipping Cream: Keep cold in the fridge right until whipping so it holds stiff peaks.
Powdered Sugar: Sweetens and thickens the frosting.
Lemon Zest & Vanilla Extract: Gives the cream a subtle, fresh citrus aroma and warmth.
Instructions
1. Preheat your oven to 180°C (350°F). Line a 9x13-inch baking pan with parchment paper and lightly grease the sides.
Make the Cake Batter
2. In a large bowl, add the softened butter, sugar, vanilla extract, lemon zest, and lemon juice. Beat with an electric hand mixer on medium speed until creamy and smooth.
3. Add the room-temperature eggs and mix until fully combined.
4. Add the sour cream, vegetable oil, and buttermilk, and mix until incorporated.
5. Add the dry ingredients: flour, baking powder, baking soda, and kosher salt, and mix on low speed until just combined. Do not overmix!
Bake and Cool
6. Pour the batter into your prepared pan and spread it out evenly with a spatula. Bake at 180°C (350°F) for 30 to 35 minutes until a toothpick inserted into the center comes out clean. Let the cake cool in the pan for 20 to 30 minutes.
Poke and Fill
7. Use the round end of a wooden spoon handle to poke holes all over the warm cake, leaving about ½ inch of space between them.
8. In a small bowl, whisk the lemon curd and 3 tablespoons of milk together until thin and pourable. Pour the curd over the cake and spread it around with a spoon or offset spatula so it flows straight into all the holes.
Frost and Serve
9. In a cold mixing bowl, combine the cold heavy cream, powdered sugar, vanilla extract, and 1 teaspoon of lemon zest. Beat with your electric mixer until stiff peaks form.
10. Gently fold the room-temperature mascarpone cheese into the whipped cream using a rubber spatula until smooth and creamy.
11. Spread the frosting over the cooled cake, make a few decorative swirls on top with an offset spatula, and garnish with extra lemon zest or thin lemon slices if you like.
Expert Tips
- Thin out the curd: Don't skip mixing the milk into the lemon curd. Straight lemon curd is too thick and will just sit on top of the cake instead of soaking into the holes.
- Room-temp dairy is key: Pull your butter, eggs, sour cream, and mascarpone out of the fridge early. Cold ingredients make the batter curdle and create lumps in the frosting.
- Measure flour right: Fluff your flour with a spoon, scoop it into the measuring cup, and level it off with the back of a knife. Packing it down will give you a heavy, dry cake.
- Don't overmix: Stop mixing as soon as the dry ingredients are just combined so the gluten doesn't overdevelop and make the cake dense.
Troubleshooting
The frosting melted when I spread it on: The cake wasn't fully cooled! Let the cake cool completely after filling so the heat doesn't melt the whipped mascarpone topping.
My frosting curdled or split: Mascarpone cheese has a high fat content and can split if it's overbeaten or mixed while cold. Make sure the mascarpone sits at room temperature for 30 minutes, and gently fold it into the whipped cream using a rubber spatula instead of using the electric mixer.
The lemon curd is sitting on top of the cake: If the curd isn't sinking in, the mixture was either too thick or the holes were too small. Be sure to mix in the 3 tablespoons of milk to loosen up the curd, and use the handle of a wooden spoon (not a fork or toothpick) so the holes are wide enough.
The cake turned out dense or rubbery: This usually means the batter was overmixed after adding the flour, or too much flour was packed into the measuring cup. Stir the flour beforehand, scoop it loosely into your cup, and mix on low speed just until combined.
Faq's
This usually happens if the holes are poked too close together or if the cake was still piping hot when you added the filling. Keep the holes ½ inch apart and let the cake cool for 20–30 minutes first.
Definitely. Store-bought or homemade both work great. Just make sure to thin it out with milk so it actually fills the holes.
Poking the cake while it's warm allows the soft cake structure to absorb the liquid filling easily. If you wait until the cake is completely cold, the surface sets and the filling will sit on top rather than sinking into the holes.
Storage and Freezing
In the fridge: Keep covered with foil or plastic wrap in the fridge for up to 4 days.
In the freezer: You can freeze the whole cake (or individual slices) in an airtight freezer-safe container for up to 3 months. Just thaw in the fridge overnight before serving.
Substitutions & Variations
White Chocolate Lemon: Fold ½ cup of mini white chocolate chips into the cake batter right before baking.
Gluten-Free: Swap the all-purpose flour for a 1:1 gluten-free measure-for-measure flour.
Greek Yogurt: Swap the sour cream for full-fat Greek yogurt at an exact 1:1 ratio.
Lemon Raspberry: Swirl ⅓ cup of seedless raspberry jam in with the lemon curd before pouring it into the holes.
Equipment
- 9x13-inch baking pan
- Parchment paper
- Electric hand mixer
- Mixing bowls
- Wooden spoon
- Whisk
- Rubber spatula
- Offset spatula
- Citrus Zester / Microplane
More lemon desserts
Chewy lemon blueberry cookies- Soft in the middle, crisp on the edges, and loaded with white chocolate chips and fresh berries.
Lemon cooler cookies- Buttery tea cookies packed with fresh citrus zest and tossed in powdered sugar.
Lemon tart- A simple buttery pastry crust filled with tangy lemon curd.
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📖 Recipe
Lemon Poke Cake w/ Mascarpone Frosting
Ingredients
- ½ cup Butter soft, room temperature
- ½ teaspoon Kosher salt
- 1 ¼ cups Granulated sugar
- 1 teaspoon Vanilla extract
- 2 teaspoon Lemon juice
- 2 tablespoon Lemon zest
- 3 Eggs
- ¼ cup Sour cream
- ⅔ cup Buttermilk
- ½ cup Vegetable oil
- 2 ¼ cups Flour AP, plain
- 1 ½ teaspoon Baking powder
- ½ teaspoon Baking soda
Assembly
- 1 cup Lemon curd store bought or from my lemon curd recipe
- 3 tablespoon Milk
Lemon mascarpone whipped cream
- 9 oz Mascarpone cheese room temperature
- 1 ½ cups Heavy cream cold
- ⅔ cup Powdered sugar
- 1 teaspoon Vanilla extract
- 1 teaspoon Lemon zest
Instructions
- Preheat your oven to 180°C (350°F). Line a 9x13-inch baking pan with parchment paper and lightly grease the sides.
Make the Cake Batter
- In a large bowl, add the softened butter, sugar, vanilla extract, lemon zest, and lemon juice. Beat with an electric hand mixer on medium speed until creamy and smooth.
- Add the room-temperature eggs and mix until fully combined.
- Add the sour cream, vegetable oil, and buttermilk, and mix until incorporated.
- Add the dry ingredients: flour, baking powder, baking soda, and kosher salt, and mix on low speed until just combined. Do not overmix!
Bake and Cool
- Pour the batter into your prepared pan and spread it out evenly with a spatula. Bake at 180°C (350°F) for 30 to 35 minutes until a toothpick inserted into the center comes out clean. Let the cake cool in the pan for 20 to 30 minutes.
Poke and Fill
- Use the round end of a wooden spoon handle to poke holes all over the warm cake, leaving about ½ inch of space between them.
- In a small bowl, whisk the lemon curd and 3 tablespoons of milk together until thin and pourable. Pour the curd over the cake and spread it around with a spoon or offset spatula so it flows straight into all the holes.
Frost and Serve
- In a cold mixing bowl, combine the cold heavy cream, powdered sugar, vanilla extract, and 1 teaspoon of lemon zest. Beat with your electric mixer until stiff peaks form.
- Gently fold the room-temperature mascarpone cheese into the whipped cream using a rubber spatula until smooth and creamy.
- Spread the frosting over the cooled cake, make a few decorative swirls on top with an offset spatula, and garnish with extra lemon zest or thin lemon slices if you like.
Notes
- Room Temperature Dairy is Essential: Pull your butter, eggs, sour cream, and mascarpone out of the fridge at least 30 to 45 minutes before baking. Room-temperature dairy prevents batter curdling and keeps the mascarpone frosting from splitting or becoming lumpy.
- Poke While Warm, Frost While Cold: Poke the holes and pour over the thinned lemon curd while the cake is still warm (about 20 minutes out of the oven) so it absorbs easily. Make sure the cake is completely cooled to room temperature before adding the mascarpone frosting, or the whipped cream will melt.
- Don't Skip Thinning the Curd: Pure lemon curd is too thick to flow into the poked holes on its own. Whisking it with 3 tablespoons of milk gives it the perfect pourable consistency so every slice gets an even distribution of lemon flavor.
- Fold the Mascarpone Gently: Once your heavy cream is whipped to stiff peaks, use a rubber spatula to gently fold in the mascarpone cheese by hand. Using an electric mixer at this stage can easily overbeat the mascarpone and cause it to separate.
- Best Served Chilled: While you can serve this cake after 1 to 2 hours of chilling, letting it sit in the fridge overnight allows the lemon curd to fully infuse into the crumb and gives you the clean, bakery-style slices.
- Measuring the Flour: Always fluff your flour with a spoon, scoop it into your measuring cup loosely, and level it off with the back of a knife. Packing flour directly from the bag will make the cake heavy and dry.
Amy says
This cake was wonderful! I made it for my brothers birthday and it was enjoyed by all! I used fresh off the tree arizona lemons and couldn’t find marscapone cheese so I substituted cream cheese. We all loved it!