Jammy Blueberry Lemon Cake
Soft, fluffy lemon cake layered with swirls of blueberry jam and triple lemon buttercream. This cake has the perfect combination of textures and is bursting with fresh, bright flavors of lemon and blueberries. Whether you make this in winter to use up the lemons from your tree or in summer to enjoy the light, vibrant flavors, this cake is perfect year round!
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This week just might prove to be the most stressful of the year for me. My students are doing evaluations of me (which is often just an opportunity for venting when it comes to teenagers). I know I’m more than what they feel like saying about me in that particular moment, but it never fails to cause the most intense fear and anxiety for me.
Pray for me or send up some good thoughts.
Anyway, I’m choosing to focus on the positive. Like the baby shower cake and cupcakes I’m making this weekend. I’m so excited for it! I’ll be sure to take lots of pics, and I may even make a mini cake and share it on the blog.
Another positive: this jammy blueberry lemon cake!
I was so in love with how it looked that I shared a photo on my Instagram in July and it was one of my most liked photos last year. Something about that jammy swirl just gets me every time. The best part is how simple it is to make. The real key is to keep it simple—less is more.
In the end, you’ll get this beautifully rustic cake that doesn’t cause anxiety over every little imperfection. Win.
Why this recipe works
The lemon cake layers has been years in the making. I’ve tried adapting various recipes, and this seems to be the perfect one. Personally, I like to cold steep the milk with peeled lemon zest overnight, which takes some forethought but does add sooooo much lemon flavor. However, if you don’t have the time, you can heat the milk and zest until steaming and let them steep for an hour. Since your eggs and butter (and milk) have to warm up for about an hour anyway, this is the faster option.
To add to the lemon flavor, I used triple lemon buttercream, which uses lemon juice, lemon zest, and lemon curd. So much lemon! The curd is key in adding a lot of flavor without watering down the buttercream.
Then there’s the jam. It’s so simple and so full of flavor. Omit the optional cinnamon, as you’ll want to maximize the fresh lemon flavor. It’s the perfect complement to the cake and buttercream, adding a bright pop of color and flavor to the filling and making those gorgeous jammy swirls on the outside.
Key ingredients
Milk. Use whole milk for a fluffy cake.
Lemon zest and juice. Don’t get any white pith in zesting, as it’s bitter.
Cake flour. You can make your own with the following recipe: for each cup cake flour, add 2 tablespoons cornstarch to a 1 cup measuring cup then spoon regular flour over it. Double sift before using.
Baking powder. Be sure it’s fresh to ensure a fluffy cake.
Salt. Sea salt is ideal.
Butter. European style is best, as it’s creamier.
Sugar. For flavor and to help the cake rise. Who knew?
Eggs. Be sue these are fresh and room temperature.
Oil. I prefer avocado (not super extra virgin, as those tend to be green) or grape seed, as those are “healthy” oils, but vegetable or canola will work, too. While you only use a tiny bit (2 tablespoons), it’s necessary to maintain moisture—using all granulated sugar (instead of part brown sugar) and replacing some of the milk with lemon juice removes some of the usual sources of moisture, so just 2 tablespoons oil makes up for this.
Vanilla. Always a must!
Triple lemon buttercream. You can make this ahead of time and refrigerate it up to 2 weeks or freeze it up to 2 months. Just be sure to give it a good stir after bringing it to room temperature.
Blueberry jam. You can use store bought, but homemade is so easy and so delicious!
How to make jammy blueberry lemon cake
1. Steep your milk. Combine milk and peeled lemon zest (avoid the white pith) in a small saucepan over medium heat. Cook until steaming then set aside to steep. Do this an hour before you want to make the cake.
2. Make your jam. You can do this ahead, or while the milk steeps. It’s fairly quick and simple! Let refrigerate while you make the cake.
3. Combine lemon juice and steeped milk. Obviously, strain the zest out first.
4. Sift and whisk dry ingredients. Be sure to double sift if making your own cake flour.
5. Process the sugar and grated lemon zest. If you don’t have a food processor, you can use a small blender.
6. Cream butter and sugar. Beat until fluffy and lighter in color.
7. Add eggs then oil and vanilla. Do this one at a time, beating on medium until fluffy and fully blended each time.
8. Alternate adding flour and milk/lemon juice. Mix on low and only mix until just barely combined after each addition.
9. Bake. Only bake until a toothpick comes out with a few moist crumbs, not completely clean, as this means it’s over baked.
10. Make the triple lemon buttercream. You can also make this ahead of time. If using homemade lemon curd, for sure make this ahead to split up your work.
11. Assemble cake. Fill with a thin layer of buttercream, pipe a ring of buttercream along the edge, then fill with jam. Frost with a thin crumb coat of buttercream, chill, then frost with buttercream and swirls of jam. It’s up to you how to do this, as long as it’s swirly and fun!
Tips and FAQ’s for this recipe
Try cold-steeping your milk and zest
This takes some forethought, but it’s actually less work. You just add the milk and zest to a jar and refrigerate it overnight, or up to 24 hours. Avoid steeping it longer as it can become bitter if steeped too long. Be sure to let it come to room temperature when ready to use.
Make your blueberry jam and lemon curd ahead of time
You can do it all at once, but it’s a lot easier to prep both ahead of time. The lemon curd needs to set in the fridge, so it’s ideal to make it at least a day ahead. The jam is very quick and easy to make, so if you have time the day of, you can make it while the ingredients come to room temperature and just let it cool in the fridge while you bake and cool the cake.
You could also make the buttercream ahead of time, to make things easier the day you’re making this cake, but that’s up to you. I like using freshly made frosting so I can use it when it’s got the perfect consistency.
Don’t over mix
This is one of those elusive rules that doesn’t always make sense. Just follow the directions as listed, which includes time frames for mixing everything. When you add the flour, you want to just barely mix it, which is completely different than when making chocolate cake. It might still be a little lumpy, but that’s okay! It’ll bake out nice and smooth.
Don’t over bake
This is a bit easier to follow, as you just need to check the cake early. If it’s still jiggling, it’s not done. If a toothpick comes out with raw batter, it’s obviously not done. You want to catch it at that perfect time when some moist crumbs come off on the toothpick, not clean. Also remember to remove it from the pan after 5-10 minutes of cooling so it doesn’t cook more.
My cake tools
Here are my must-have tools I use for making this cake. Affiliate links provided.
Mesh sieve (because sifting is KEY for a fluffy cake)
All-rubber spatula (this makes scraping the bowl easier as the batter and frosting doesn’t get all over a wooden handle!)
Silicone liners for 8” cake (or for 6” cakes)
8” aluminum cake pans or 6” aluminum cake pans (I’ve found nonstick doesn’t bake as evenly)
Offset spatula for frosting the cake
Jammy Blueberry Lemon Cake
- prep time: 40-45 minutes
- steep time: 1 hour
- bake time: 25-30 minutes
- total time: 2 hours, 15 minutes, plus cooling time (includes making the buttercream and jam)
servings: 12-16
Ingredients:
- ¾ cup whole milk
- peeled lemon zest from 2-3 lemons
- ¼ cup fresh lemon juice
- 2 cups plus 2 tablespoons cake flour, spooned then leveled*
- 2 teaspoons baking powder
- ½ teaspoon sea salt
- ¾ cup unsalted butter, room temperature
- 1 ⅔ cups granulated sugar
- 2 tablespoons grated lemon zest (2 large lemons)
- 3 large eggs, room temperature
- 2 tablespoons avocado or vegetable oil
- 1 tablespoon vanilla extract
- one batch triple lemon buttercream
- one batch blueberry jam (or one jar store bought)
Instructions:
- Note: if you want to make homemade lemon curd for the buttercream (highly recommended!), do this ahead of time. It will last in the fridge up to 2 weeks.
- When you take your ingredients out to warm up, about an hour before you make the cake, place the milk and peeled zest (no white pith) from 2-3 lemons in a small saucepan over medium heat. Cook, stirring frequently, until the milk begins to steam and there are bubbles forming along the edges. Remove from heat and let steep 1 hour, until cooled to room temperature.
- Next, make your blueberry jam (if using homemade). Let it set in the fridge while you make the cake.
- When the milk is done steeping, strain the zest out using a fine mesh sieve, gently pressing on the zest to get all of the oils out. Discard the zest. Combine the milk and lemon juice. You may need to add an extra splash of milk or lemon juice to ensure you have one full cup of lemon milk. Stir and let sit 5-10 minutes. It will turn into buttermilk while you make everything else.
- Preheat oven to 325F/165C. Lightly grease and flour two or three 8” or 9” cake pans and line with parchment paper. I like using three pans so I can have more filling. If making a 6” cake, use three to four pans.
- Sift and whisk together cake flour, baking powder, and salt. Set aside.
- In a food processor or blender, pulse the sugar and lemon zest, until well blended and no large chunks of zest remain. It should slightly resemble wet sand.
- Beat the butter on high until smooth, about 30 seconds. Add the lemon sugar and beat on high until light and fluffy, 2-3 minutes. Scrape the bowl as needed.
- Add the eggs, one at a time, beating on high for about 30 seconds until well-blended. Scrape the bowl between eggs. Add the oil and vanilla and beat on high until well-blended, about 30 seconds. Scrape the bowl again.
- Add half the flour and mix on low until just barely combined. Add the milk and beat on low until just barely combined. It will look a little separated, but don’t worry. Add the rest of the flour and mix on low until just barely combined, with some streaks of flour still visible. Scrape the sides and bottom of the bowl then beat on medium for 1-2 seconds, just to quickly incorporate the mixture on the bottom (do not overmix).
- Divide evenly between prepared pans and spread evenly with a spatula. Bake for 25-30 minutes (less if using three pans), until a toothpick inserted in the middle comes out with a few moist crumbs. Begin checking around 20 minutes so it doesn’t overbake. Rotate pans halfway if not using a convection oven.
- Let cake cool in pans 5-10 minutes then remove to a wire rack to cool completely.
- While the cakes cool, make the triple lemon buttercream. Place about ½ cup of it into a piping bag.
- Fill the cake by adding a thin layer of buttercream on the bottom layer. Pipe a ring of buttercream around the edge of the cake. Spread a layer of jam inside this ring. You can make it as thin or thick as you’d like, but don’t let it be thicker than about ¼ inch or the cake will slide too much. Continue until all layers are filled. Spread a thin layer of buttercream on the top and sides of the cake. If some jam squeezes out, just spread it into the frosting. Refrigerate the cake for 10-20 minutes to set it.
- Add a few dollops of jam to the remaining buttercream. Without stirring it, scoop some frosting and jam onto your offset spatula and spread onto the cake. The goal is to get jammy swirls, so don’t worry about perfection.
Enjoy!
Cake will last at room temperature for 3-5 days. (If using homemade lemon curd in the frosting, you’ll need to refrigerate it). Seal cut cake by placing a piece of plastic wrap right up against the cut edge and sealing it against the buttercream. Cover leftovers well or in an airtight container.
*To make your own cake flour, add 2 tablespoons cornstarch to your 1 cup measuring spoon then cover with all-purpose flour, spooning it in then leveling with the back of a knife. Repeat this for the second cup. Double sift the flour before using.
