If you’re a lemon lover, this lemon bar cake is your dream mash-up. It’s part lemon bar, part lemon cake, stacked into one dessert that manages to be gooey, buttery, tart, and fluffy all at once. We start with a crumbly shortbread crust, layer on a gooey lemon filling, then bake a soft lemon cake right on top. Every bite has a little crunch, a little tang, and a lot of brightness.


I love this lemon bar cake because it looks impressive but is surprisingly simple to pull together. It uses pantry basics plus a whole lot of lemon, and together the layers bake up into something really special.

Ingredient notes & substitutions

See the recipe card at the end of this post for the full ingredient list & quantities.

  • Unsalted butter is used in both the crust and the cake. It’s melted for the shortbread and softened for the cake, adding richness and structure in each layer.
  • The shortbread crust uses powdered sugar instead of granulated, which helps it bake up more tender and crumbly.
  • All three layers are made with simple all-purpose flour, so nothing fancy is needed here.
  • The flavor of this cake comes from plenty of fresh lemon juice and zest. Freshly squeezed juice and zest give the best bright citrus flavor – bottled juice won’t taste the same.
  • Room temperature eggs are important for this recipe. They set the lemon filling and give structure to the cake layer.
  • Sour cream & buttermilk keep the cake moist and soft, and also adds a subtle tang.
  • A splash of vanilla helps balance the flavor, and lemon extract (optional, but recommended) gives the cake an extra citrus boost.

Step by step instructions

See the recipe card at the end of this post for the full recipe instructions.

STEP 1: Make the shortbread crust. Mix melted butter, powdered sugar, flour, salt, and vanilla until crumbly.

STEP 2: Press shortbread mixture into pan. Press into your springform pan, going slightly up the sides to create a shallow barrier. Bake until lightly golden and matte. Let the crust cool for about 5 minutes.

STEP 3: Prepare lemon filling. Whisk together sugar and flour. Add the eggs, lemon juice, and lemon zest and whisk to combine. Place the pan back in the oven, then carefully pour in the filling. Bake until set.

STEP 4: Whisk dry cake ingredients. Whisk flour, baking powder, baking soda, and salt.

STEP 5: Combine cake wet ingredients. Rub the lemon zest into the sugar, then beat with butter and oil until light and fluffy. Add eggs & extracts, and mix until combined.

STEP 6: Alternate adding the dry ingredients and buttermilk/sour cream. Mix in the dry ingredients, alternating with sour cream and buttermilk. The batter should be smooth and spreadable.

STEP 7: Bake the cake layer. Layer the cake batter on top of the lemon filling and bake until golden, set, and a toothpick comes out clean.

Recipe FAQ

Can I make this ahead of time?

Yes! This lemon bar cake keeps well in the fridge for up to 2-3 days. Chilling also makes slicing easier.

Why did my crust turn soggy?

Most likely too much filling was added, or the crust wasn’t baked and/or cooled enough before pouring. Let the crust rest for a few minutes and don’t fill past the top edge.

Can I use a different pan?

I recommend a springform pan for this recipe – it makes removing the cake so much easier. The recipe is written for an 8-inch springform, but I’ve included bake times for a 9-inch pan in the notes. You could also turn this into bars by lining a square pan with parchment and lifting them out once cooled.

Baking in grams

I rely on gram measurements when testing recipes because they offer the highest level of accuracy (and less cleanup!). Unlike volume measurements, which can vary, grams provide a reliable and consistent standard. I carefully test all of my recipes using this kitchen scale, therefore I cannot guarantee the outcome when using volume measurements. However, volume measurements are available in the recipe card.

Have you tried this recipe?

I would love to know how it turned out! Leave a star rating & review below and tag @sturbridgebakery on Instagram so I can see photos & videos of your yummy bakes! 

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Lemon Bar Cake

Author: Jess Italiano
If you’re a lemon lover, this lemon bar cake is your dream mash-up. It’s part lemon bar, part lemon cake, stacked into one dessert that manages to be gooey, buttery, tart, and fluffy all at once.
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Ingredients
 

Shortbread Crust

  • 85 grams (6 tablespoons) unsalted butter, melted
  • 40 grams (1/3 cup) powdered sugar
  • 170 grams (1 ¼ cups + 1 tablespoon) all purpose flour
  • ¼ teaspoon fine sea salt
  • 1 teaspoon vanilla extract

Filling

  • 200 grams (1 cup) granulated sugar
  • 23 grams (3 tablespoons) all purpose flour
  • 3 eggs, room temperature
  • 120 grams (½ cup) fresh lemon juice, about 3-4 lemons
  • zest of 1 large lemon

Cake

  • 130 grams (1 cup) all purpose flour
  • 1 teaspoon baking powder
  • ¼ teaspoon baking soda
  • ¼ teaspoon fine sea salt
  • 150 grams (¾ cup) granulated sugar
  • zest of 3 large lemons
  • 113 grams (½ cup) unsalted butter, room temperature
  • 30 grams (2 tablespoons) vegetable oil
  • 2 eggs, room temperature
  • 1 teaspoon vanilla bean paste or extract
  • ½ teaspoon lemon extract
  • 60 grams (¼ cup) sour cream, room temperature
  • 60 grams (¼ cup) buttermilk, room temperature

Instructions
 

Shortbread Crust

  • Preheat oven to 350F. Line the bottom & sides of an 8-inch springform pan with parchment paper. Wrap outside in foil just in case of leaks. See recipe notes for the bake times of a 9-inch springform pan.
  • Mix melted butter, powdered sugar, vanilla, salt, and flour until crumbly. Press evenly into pan and slightly up the sides to create a shallow barrier. Prick with a fork so the air as a place to escape. Bake for 20-23 minutes until golden on the edges and matte on top.
    85 grams unsalted butter, 40 grams powdered sugar, ¼ teaspoon fine sea salt, 1 teaspoon vanilla extract, 170 grams all purpose flour

Filling

  • In a bowl, whisk sugar and flour. Add eggs, lemon juice, and zest; whisk until smooth. Let the baked crust cool for 5 minutes at room temperature before adding filling – this helps secure the crust.
    200 grams granulated sugar, 23 grams all purpose flour, 3 eggs, 120 grams fresh lemon juice, zest of 1 large lemon
  • Place the pan back in the oven, then carefully pour in the lemon filling. This reduces the risk of spillage and keeps the crust intact. If it looks like it will overflow or reach the very top edge of the crust, stop and don’t add the last bit – too much liquid can make the crust soggy.
  • Bake for approximately 20 minutes at 350F, until it's set.

Cake

  • Whisk flour, baking powder, baking soda, and salt. Set aside.
    130 grams all purpose flour, 1 teaspoon baking powder, ¼ teaspoon baking soda, ¼ teaspoon fine sea salt
  • In a separate bowl, rub lemon zest into sugar until fragrant and the natural oils have released. Beat in butter and oil until light and fluffy.
    150 grams granulated sugar, zest of 3 large lemons, 113 grams unsalted butter, 30 grams vegetable oil
  • Mix in eggs, vanilla, and lemon extract.
    2 eggs, 1 teaspoon vanilla bean paste or extract, ½ teaspoon lemon extract
  • Add dry ingredients in two parts, alternating with sour cream and buttermilk. Mix until just smooth. Layer gently over lemon filling.
    60 grams sour cream, 60 grams buttermilk
  • Bake for 30–33 minutes at 350F, until golden and a toothpick inserted into the cake comes out clean. Let cool for 35-40 minutes at room temperature.
  • Top with powdered sugar or whipped cream & enjoy!

Notes

Pan Size Note
  • This recipe is written for an 8-inch springform pan (8–10 servings).
  • For a 9-inch springform pan, in testing, bake times were:
    • Crust: 20-22 minutes
    • Lemon filling: ~20 minutes
    • Cake: 30-33 minutes
Tried this recipe?Let us know how it was!