Vegan Lemon Pistachio Olive Oil Cake with Strawberry Chia Jam & Pistachio Buttercream Frosting
This lemon pistachio olive oil cake is filled with a layer of fresh strawberry jam and coated in a pistachio buttercream frosting to create the ultimate dreamy and super tender lemon cake! Delicious, fluffy, and absolutely perfect for any summer occasion.
One of my favorite things about my lemon pistachio granola recipe is that it’s reminiscent of a slice of lemon cake. However, despite how delicious it is, granola is most definitely not cake, and it left me craving an actual slice of lemon pistachio olive oil cake. And once I started daydreaming of this cake flavor, I couldn’t let it go - not until I could finally taste the actual cake and satisfy that craving. And the more I thought about it, the more components came to mind - a fresh berry jam to add an extra summery element, a buttercream frosting to add extra decadence. The result? A lemon and pistachio olive oil cake that’s stuffed with a layer of fresh strawberry jam (because strawberries, lemons, and pistachios are a heavenly combo) and coated in a pistachio buttercream frosting to tie everything together. It’s delicious, fluffy, summer-y, and I think you’ll love it as much as I do!
Why You’ll Love this Cake
Delicious flavors and layers. First, the base cake layer. Lemon olive oil cake is one of my favorite types of cakes - I love the pairing of zippy lemon with the rich and complex notes of olive oil - and to give the classic a twist, I layered in the most perfect flavor complement I could think of: pistachios! Second, a layer of fresh strawberry jam for freshness and texture contrast. Because if there’s something that could make the nearly-perfect combination of a lemon pistachio cake even more delicious, it’s strawberries! Last, but certainly not least, a rich buttercream frosting. Since this cake uses actual pistachios, not any artificial pistachio flavorings, it doesn’t taste super strongly like pistachios. So to highlight the pistachio flavor a bit more, and to bring all the delicious flavors together, frosting is mixed with extra pistachios.
Summer-y! 🍓 Fresh, peak season strawberries create a jam that helps infuse those summer vibes into this cake! It’s a great way to use up a lot of fresh strawberries - especially if you’re anything like me and you’ve (once again) bought too many because you can’t control yourself around seasonal berries at the farmers’ market.
Dreamy texture. This cake has an ultra fluffy and tender texture, which keeps it light and makes it ideal for summer (because let’s be honest no one wants to sit in the heat with a stomach full of heavy cheesecake)! And because this is an olive oil-based cake, it actually gets more moist after a few hours and retains moisture better than butter-based cakes, meaning your day 3 leftovers won’t end up tasting bone dry. To maximize moisture, I recommend baking the cake layers the day before you plan on serving the finished cake.
Ingredient Overview
Cake Layers
All-purpose flour. Half of this cake’s base is the plain, all-purpose flour you (most likely) already have in your pantry.
Raw pistachios. The other half of the base. Raw pistachios get processed into very fine bits to create a “flour” that gives the cake its pistachio flavor and green hue! They also help give the cake its soft, fluffy texture while adding some extra fiber and protein.
Baking soda and baking powder. For rise!
Aquafaba. I.e. the leftover liquid in a can of chickpeas! When whipped, aquafaba turns into a foamy substance that acts similarly to egg whites to provide structure for the cake, while also contributing to its ultra light, tender texture.
Fresh lemon zest and juice. For that bright, beautiful lemon flavor! Be sure to buy fresh lemons - you’ll obviously need them for the zest, and freshly squeezed lemon juice is equally important in giving the cake the absolute best flavor.
Non-dairy milk. To combine with the lemon juice and form a “buttermilk” that will react with the baking soda and help the cake rise. I used oat milk, but other non-dairy milks should also work.
Extra virgin olive oil. For moisture! Olive oil also pairs perfectly with lemons and pistachios to give the cake its unique flavor.
Cane sugar. Nothing fancy here - the cake uses basic cane sugar for its sweetness. I don’t recommend any substitutions here - the “plainness” of cane sugar is what really allows the other flavors, like lemon and pistachio, to shine!
Vanilla extract. For a hint of warmth that perfectly complements the lemon and pistachio flavors.
Strawberry Chia Jam
Fresh strawberries. The base of the jam! Using fresh, in-season strawberries is key for achieving an ultra rich strawberry flavor.
Maple syrup. To sweeten the jam! I don’t love jams that are ultra sweet, so this jam isn’t in your face sweet and still has a tiny bit of zing to it, which I find helps contrast the cake’s ultra sweet frosting quite nicely. The final cake is plenty sweet, but if you like your jams on the sweeter side, feel free to add a bit more maple syrup (or any kind of sweetener) to adjust the sweetness to taste.
Lemon juice. For a bit of acidity to balance the overall flavor of the jam.
Chia seeds. These help thicken the jam while also adding a tiny boost of healthy omega-3 fatty acids into the cake - because who doesn’t love some unexpected nutrients and extra fiber in their dessert?!
Pistachio Buttercream Frosting
Pistachios. To infuse the frosting with a bit more of that delicious pistachio flavor! Use a small food processor to process some raw pistachios until they form a paste, then continue processing them until they turn into a “butter” (think a similar consistency of a creamy almond butter here). Once you’ve got your pistachio “butter,” mix it in with your vegan butter before you start incorporating the powdered sugar.
Vegan butter and powdered sugar. The two other base ingredients in buttercream frosting! I used Earth Balance vegan butter sticks here.
Tips for Baking this Cake
Cake Layers
Use a food scale or the “spoon and level” method to weigh the flour. For the best results in baking, use the gram measurements provided in the recipe to weigh the flour as they’re more accurate and will yield more consistent results! If you don’t have a food scale, use the “spoon and level” method to avoid using too much flour (you don’t want a dry, dense cake!). To do this, “fluff” the flour to aerate it. Then, spoon the flour into a measuring cup until it overflows slightly, and use the back of a knife to “level” the excess flour off the top. (PS - I highly recommend investing in a food scale - they’re cheap and invaluably useful for both baking and cooking!)
Process the pistachios into a fine meal. No one wants giant bits of pistachios inside their cake! To achieve that fluffy cake texture, you’ll need to use a food processor to pulse the pistachios into finely ground bits that resemble flour. For the best results, I recommend doing this in two batches using the smaller bowl of a food processor (if yours has multiple sizes). Just be careful to not overprocess them as they’ll eventually start turning into a pistachio paste, and then a butter - not what you want for the cake, but note you’ll want to do this with additional pistachios later so that you can incorporate the butter in the frosting! If you prefer, feel free to substitute the pistachios with store bought finely ground pistachio flour (it’s available for purchase through various online retailers).
Zest the lemons before juicing. This cake requires both lemon zest and juice, so don’t forget to zest your lemons before juicing them! Nothing is sadder than desperately trying to zest squeezed lemons.
Don’t overmix! The most important tip for a successful cake is to RESIST the urge to overmix the wet and dry ingredients in order to avoid overworking the gluten! Mix them together just until the dry ingredients have been incorporated in with the wet ingredients to form a batter.
Bake the batter ASAP after mixing. Once the dry ingredients touch the wet ingredients, baking soda begins reacting immediately to release carbon dioxide, which creates little pockets that help the cake rise. This means you’ll want to work quickly to mix everything together and get those cakes into the oven to bake ASAP!
Let the cakes cool fully before frosting. This tip applies anytime you bake a cake, but it’s particularly important with this cake because it’s extra tender and more fragile since pistachios make up half the base. Cooling the cakes completely ensures they’ll retain their structure better!
Optional, but recommended: Bake the cakes the night before you plan to frost/serve the finished cake. If possible, I recommend baking the cake layers the night before you plan on serving the finished cake. Not only does this ensure the cake layers will be fully cooled in time for frosting, but they’ll actually become more moist as they sit overnight, so the finished cake will taste even better! Note you’ll still want to make the jam and frosting right before you’re getting ready to assemble/decorate the cake so that they’re fresh.
Pistachio Buttercream Frosting
Use room temperature butter. To get the best frosting texture, let your vegan butter come to room temperature before you start beating it.
Process the pistachios into a butter. Remember how I mentioned you didn’t want to process your pistachios too much for the cakes because they’ll eventually turn into a butter if you do? Well, you’ll actually want to do that now so you can incorporate a pistachio butter that into the frosting! Once the pistachios are finely ground, just keep processing them and they’ll eventually turn into a butter. Alternatively, you can also use a store-bought raw pistachio butter here.
Let’s bake!
Lemon Pistachio Olive Oil Cake with Strawberry Chia Jam & Pistachio Buttercream Frosting
Vegan
Serves 8-10
Ingredients
For the lemon pistachio olive oil cakes:
200 grams/1 ½ cups raw pistachios (shelled)*
180 grams/1 ½ cups (spooned & leveled) all-purpose flour
2 teaspoons baking powder
¼ teaspoon baking soda
½ teaspoon fine salt
¼ cup non-dairy milk (I used oat)
¼ cup freshly squeezed lemon juice (zest the lemons before juicing them!)
½ cup aquafaba (i.e. the liquid from a can of chickpeas)
½ cup extra virgin olive oil
⅔ cup cane sugar
2 tablespoons lemon zest
1 ½ teaspoons vanilla extract
For the strawberry chia jam:
4 cups fresh strawberries, stemmed and quartered (measured after stemming and cutting)
¼ cup maple syrup
1 tablespoon lemon juice
2 tablespoons chia seeds
For the pistachio buttercream frosting:
½ cup/67 grams raw pistachios OR ¼ cup raw pistachio butter
8 tablespoons (1 stick) vegan butter, softened at room temperature (I used Earth Balance)
1 ½ cups/180 grams powdered sugar
To decorate/serve (optional):
Ground pistachios
Fresh strawberries
Directions
Cakes:
Pre-heat oven to 350°F. Line the bottoms of two 8-inch round cake pans with round pieces of parchment paper.
Make the pistachio flour. Working in two batches, add the pistachios to the small bowl of a food processor and pulse until very finely ground. (Be careful not to overprocess the pistachios as they’ll start to turn into a paste.) Transfer the pistachio flour to a medium bowl.
To the same bowl, add the flour, baking soda, baking powder, and salt and whisk to combine.
In a small bowl or measuring cup, combine the lemon juice and non-dairy milk and set aside to curdle.
Add the aquafaba to a medium bowl and use a handheld electric mixer to whip the aquafaba on medium speed for ~60 seconds until very foamy. Set aside briefly.
To a large bowl, add the olive oil and sugar and use the handheld electric mixer to beat them together until thoroughly incorporated. Add the milk/lemon juice mixture, lemon zest, and vanilla extract and mix again to incorporate. Add in the whipped aquafaba and mix again gently until combined.
Add in half the dry ingredients and use the lowest setting on the mixer to combine. Then add in the remaining dry ingredients and continue mixing on the lowest speed just until the dry and wet ingredients are incorporated, being careful not to overmix.
Divide the batter evenly between the two prepared cake pans (if you have a food scale, use it to weigh the batter!) and transfer to the oven and bake until a toothpick inserted near the middle comes out nearly clean, about 23-26 minutes (mine took 25 minutes). Remove from oven and let the cakes cool in the pans for 20 minutes.
Run a knife along the exterior of the cakes, then gently and very carefully transfer the cakes to a wire rack to cool completely before assembling and frosting, about ~2 hours. If you plan on assembling/serving the cake the next day, cover the cake layers (after they’ve cooled fully) and store overnight at room temperature - the cakes will become more moist with time.
Jam:
In a medium saucepan, combine the strawberries, maple syrup, and lemon juice and bring to a boil, then turn down the heat and simmer for 5 minutes, stirring occasionally, until the berries start to soften.
Use a metal potato masher, fork, or wooden spoon to mash the berries. Continue simmering and stirring frequently until the jam has reduced and thickened, about 15 more minutes.
Remove from heat and let cool for 5 minutes, then stir through the chia seeds and allow the jam to cool and continue thickening.
Frosting:
While the jam is cooling, make the frosting. Add the pistachios to the small bowl of a food processor and process until they turn into a butter, about 10 minutes, pausing to scrape the sides as needed. Alternatively, you can skip this step and use ¼ cup of store-bought raw pistachio butter for the frosting.
In a medium to large bowl, use a handheld electric mixer to beat the vegan butter and pistachio butter until fluffy. Gradually add in the powdered sugar (½ cup at a time) and beat together until fully incorporated.
Assembly:
Once the cakes have cooled completely, work very gently to assemble and frost the cake as the cake layers are on the fragile side. Spread the jam onto the top of one of the cake layers (you may have a very small amount of jam leftover), then carefully set the second cake layer on top.
Cover the top and sides with frosting (or leave the sides “naked” for a more rustic look), using an offset spatula to smooth. Top with fresh strawberries and crushed pistachios (optional), then transfer the cake to the fridge to allow the frosting to firm up before serving.
Store leftover frosted cake in the fridge, covered. Let leftover slices come to room temperature for about ~10 minutes before serving to allow the crumb to soften.
Notes:
*If you don’t want to make your own pistachio flour, you can substitute the pistachios with 200 grams of store bought pistachio flour.
**Recipe originally published 6/25/2021; last updated 7/21/2022.
If you enjoyed this cake, please share the recipe, leave a review in the comments below, and/or tag me on Instagram (@teostinykitchen) so I can see and share your beautiful cake!