This high altitude lemon bar cake has three layers of moist and tender lemon cake baked right on top of a shortbread cookie crust. The cake is filled with tangy lemon curd, and frosted with lemon cream cheese buttercream.
You might also love these oatmeal lemon cream crumb bars, lemon lush dessert, and lemon poppy seed cake.
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Why You’ll Love This Recipe
Moist and Dense. This is a more dense lemon cake that’s very tender, and so good with the crunchy shortbread crust underneath, the soft lemon curd and creamy buttercream.
High Altitude Tested. I develop all the recipes on my site for Denver’s altitude of 5,280 feet. If you’re at a lower or higher elevation, please see my FAQs for guidance on adjusting recipes for your altitude.
See the recipe card at the end of the post for the full ingredients list and instructions.
Ingredients
Shortbread Crust and Cake
- Flour. You’ll be using all purpose flour for the shortbread crust, but cake flour for the cake layer. Cake flour has a lower percentage of protein, for a softer, more tender texture.
- Sugar. Adds sweetness and moisture.
- Salt. Balances the sweetness.
- Butter. Use unsalted butter for both the crust and the cake, or omit/reduce the extra salt in the recipe.
- Lemons. You’ll be using both the lemon zest and lemon juice in the cake.
- Cream Cheese. Adds moisture and richness to the cake.
- Eggs. Gives the cake moisture, structure and strength.
- Vanilla Extract. Flavor.
- Baking Powder. Leavening agent, so the cake isn’t too dense.
- Milk. Moisture.
Buttercream and Filling
- Butter + Shortening + Cream Cheese. When making cream cheese frosting or buttercream, I prefer to use a combination of unsalted butter, shortening and cream cheese, which gives it flavor as well as more stability. Cream cheese frosting made with just cream cheese is far too soft for a layer cake, and requires far more powdered sugar to stiffen it.
- Lemon Paste or Extract. Flavor.
- Powdered Sugar. Sweetens and thickens the frosting.
- Meringue Powder + Corn Starch. Adds stability and improves the texture.
- Salt. Balances the sweetness.
- Lemon Curd.
Instructions
Getting Ready
- Preheat the oven to 350 F, and position a rack in the center of the oven.
- Line the bottom of three 8-inch round cake pans with a circle of parchment paper. Lightly spray the bottom and sides of the pan with non-stick baking spray.
Crust
- In a bowl, combine the flour, sugar and salt. Add the cold butter, and use a pastry cutter to cut the butter into the flour until crumbly, and the chunks of butter are no bigger than peas.
- Divide the crumbs between the cake pans, then firmly press the crumbs in an even layer against the bottom of the pans.
- Set aside until needed.
Make the Cake Batter
- Use a microplane zester to zest your lemons. You’ll be using the lemon zest, as well as the juice from your lemons, and you’ll need approximately 2 large lemons or 4 small lemons to get enough zest and juice.
- In the bowl of your stand mixer fitted with the paddle attachment, combine the sugar with the lemon zest. Use your fingers to rub the lemon zest into the sugar until very fragrant.
- Add the butter and cream cheese, and beat on medium speed (#4-6 on a Kitchen Aid mixer) for 7 minutes. Scrape the bowl down several times while mixing.
- Beat in the eggs, 1 at a time, beating in each egg on medium speed for 1 full minute before adding the next egg. Add the vanilla.
- In a bowl, sift together the flour, salt and baking powder. Separately, stir together the milk and lemon juice; the mixture will curdle. With the mixer on low, add the flour mixture in 3 additions, alternating with the lemon milk, starting and ending with the flour. Increase speed to medium and beat for 15 seconds.
Bake the Cake
- Divide the batter between the prepared pans, pouring the batter right on top of the crust. Bake for about 35-40 minutes, until the tops spring back when lightly touched, or a toothpick or cake tester inserted in the center comes out clean.
- Set the pans on a cooling rack, and cool the cakes for 30 minutes. As the cakes cool, the puffed tops will deflate a bit and the cake layers will flatten. Run a sharp knife around the sides of the pans, remove the cakes from the pans, and set on a cooling rack (with the bottom crust against the rack) to cool completely before frosting. If you like, use a sharp knife to trim the dark edges from around the cake.
Make the Buttercream
- In the bowl of your stand mixer fitted with the paddle attachment, beat the softened butter, shortening and cold cream cheese for 1-2 minutes, until smooth. Beat in the lemon paste or extract.
- In a separate bowl, combine the powdered sugar, meringue powder, corn starch and salt. With the mixer on low, add the sugar mixture by spoonfuls. Turn the speed up to medium, and beat for 4-5 minutes, until smooth and fluffy. If the buttercream is too thick, add several spoonfuls of the lemon curd. Turn the speed down to “stir” and mix for 1 more minute.
Baker’s Note: Frosting this cake will be difficult for beginner bakers, since the lemon curd and cream cheese frosting makes the layers slippery. I recommend this recipe only for those with some experience in assembling and frosting layer cakes.
Assemble the Cake
- Set one of the cooled cakes, crust side down, on a base plate. Frost the top of the cake with a thin layer of the buttercream, leaving a little “dam” around the edges. Spread about 1/4 – 1/3 cup lemon curd over the buttercream, stopping 1 inch from the edges.
- Repeat with the next layer of cake, buttercream and lemon curd, then place the last layer of cake on top.
- Working carefully so the cake layers don’t slide around, frost the top and sides of the cake with a thin crumb coat of buttercream. Place the cake in the refrigerator and chill for at least 1 hour, before frosting with a final coat of buttercream.
- If you have any leftover buttercream, fit a piping bag with tip 1M, fill with buttercream, and pipe drop flowers over the top and sides of the cake.
Be sure to read all of my BAKING FAQs where I discuss ingredients, substitutions and common questions with cake making, so that you can be successful in your own baking! I also suggest reading these comprehensive posts on making Perfect American Buttercream, How to Stack, Fill, Crumb Coat and Frost Layer Cakes and How to Use Piping Bags.
Frequently Asked Questions
How should I store lemon bar cake?
Store the leftover cake in an airtight container in the refrigerator for up to 3 days.
Can I make this recipe without the shortbread layer?
Yes, if you prefer to bake the cake without the layer of shortbread, that will work just fine. The cake will take about the same amount of time, or a few minutes less to bake.
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High Altitude Lemon Bar Cake
This high altitude lemon bar cake has three layers of moist and tender lemon cake baked right on top of a shortbread cookie crust. The cake is filled with tangy lemon curd, and frosted with lemon cream cheese buttercream.
All recipes on Curly Girl Kitchen are developed for high altitude at 5,280 feet. See FAQs for adjusting to higher or lower elevations.
Equipment
- Stand Mixer with Paddle Attachment
- 8-inch cake pans (x3)
Ingredients
Crust
- 1 ½ cups all-purpose flour, fluffed, spooned and leveled
- ½ cup granulated sugar
- ½ tsp coarse Kosher salt (if using table salt, use half the amount)
- ¾ cup cold unsalted butter, cut into tablespoons
Cake
- 2 ¼ cups granulated sugar
- 2 tbsp fresh lemon zest (from 2 large lemons or 4 small lemons)
- 1 cup unsalted butter, softened to room temperature
- 4 oz full fat cream cheese (block style), softened to room temperature
- 4-5 large eggs (Use 4 or 5 large eggs to equal 1 full cup of eggs, filled to the 8 ounce line in a liquid measuring cup.)
- 2 tsp vanilla extract
- 3 cups cake flour, fluffed, spooned and leveled
- 1 tsp coarse Kosher salt (if using table salt, use half the amount)
- 1 ½ tsp baking powder
- 1 cup whole milk
- â…“ cup fresh lemon juice
Buttercream and Filling
- ½ cup unsalted butter, softened to room temperature
- ½ cup shortening
- 8 oz block style full fat cream cheese, cold
- 2 tsp lemon paste or lemon extract
- 5 cups powdered sugar
- 1 tbsp meringue powder
- 2 tbsp corn starch
- ¼ tsp coarse Kosher salt (if using table salt, use half the amount)
- 1 jar (12 oz) lemon curd
Instructions
Getting Ready
- Preheat the oven to 350 F, and position a rack in the center of the oven.
- Line the bottom of three 8-inch round cake pans with a circle of parchment paper. Lightly spray the bottom and sides of the pan with non-stick baking spray.
Crust
- In a bowl, combine the flour, sugar and salt. Add the cold butter, and use a pastry cutter to cut the butter into the flour until crumbly, and the chunks of butter are no bigger than peas.
- Divide the crumbs between the cake pans, then firmly press the crumbs in an even layer against the bottom of the pans.
- Set aside until needed.
Cake
- Use a microplane zester to zest your lemons. You'll be using the lemon zest, as well as the juice from your lemons, and you'll need approximately 2 large lemons or 4 small lemons to get enough zest and juice.
- In the bowl of your stand mixer fitted with the paddle attachment, combine the sugar with the lemon zest. Use your fingers to rub the lemon zest into the sugar until very fragrant.
- Add the butter and cream cheese, and beat on medium speed (#4-6 on a Kitchen Aid mixer) for 7 minutes. Scrape the bowl down several times while mixing.
- Beat in the eggs, 1 at a time, beating in each egg on medium speed for 1 full minute before adding the next egg. Add the vanilla.
- In a bowl, sift together the flour, salt and baking powder. Separately, stir together the milk and lemon juice; the mixture will curdle. With the mixer on low, add the flour mixture in 3 additions, alternating with the lemon milk, starting and ending with the flour. Increase speed to medium and beat for 15 seconds.
- Divide the batter between the prepared pans, pouring the batter right on top of the crust. Bake for about 35-40 minutes, until the tops spring back when lightly touched, or a toothpick or cake tester inserted in the center comes out clean.
- Set the pans on a cooling rack, and cool the cakes for 30 minutes. As the cakes cool, the puffed tops will deflate a bit and the cake layers will flatten. Run a sharp knife around the sides of the pans, remove the cakes from the pans, and set on a cooling rack (with the bottom crust against the rack) to cool completely before frosting. If you like, use a sharp knife to trim the dark edges from around the cake.You can also wrap the cake layers individually in plastic wrap and freeze for up to 3-6 months. Thaw completely before assembling and frosting your cake.
Buttercream and Filling
- In the bowl of your stand mixer fitted with the paddle attachment, beat the softened butter, shortening and cold cream cheese for 1-2 minutes, until smooth. Beat in the lemon paste or extract.
- In a separate bowl, combine the powdered sugar, meringue powder, corn starch and salt. With the mixer on low, add the sugar mixture by spoonfuls. Turn the speed up to medium, and beat for 4-5 minutes, until smooth and fluffy. If the buttercream is too thick, add several spoonfuls of the lemon curd. Turn the speed down to "stir" and mix for 1 more minute.
- Set one of the cooled cakes, crust side down, on a base plate. Frost the top of the cake with a thin layer of the buttercream, leaving a little "dam" around the edges. Spread about 1/4 – 1/3 cup lemon curd over the buttercream, stopping 1 inch from the edges.
- Repeat with the next layer of cake, buttercream and lemon curd, then place the last layer of cake on top.
- Working carefully so the cake layers don't slide around, frost the top and sides of the cake with a thin crumb coat of buttercream. Place the cake in the refrigerator and chill for at least 1 hour, before frosting with a final coat of buttercream.Baker's Note: Frosting this cake will be difficult for beginner bakers, since the lemon curd and cream cheese frosting makes the layers slippery. I recommend this only for those with some experience in assembling and frosting layer cakes.
- If you have any leftover buttercream, fit a piping bag with tip 1M, fill with buttercream, and pipe drop flowers over the top and sides of the cake.
Notes
Store the leftover cake in an airtight container in the refrigerator for up to 3 days.
I made this cake this weekend for my mother in law’s birthday and it was fantastic! I live at about 6500′ and didn’t make any changes to the recipe and the cakes came out beautifully. Tons of bright lemon flavor in every bite and the cookie bottoms were a nice touch. Will definitely be making this one again. Thank you so much for all of your delicious recipes as it really helps take a lot of the guesswork out of baking for those of us at high altitudes 😊
Can I use regular flour?
Please see my FAQs: https://curlygirlkitchen.com/baking-faqs/