This wonderful layer cake is great for an early summer dessert, highlighting fresh-and-fruity flavors during blueberry season. Lemon and blueberry are a classic combination, but I added something a little different into the mix and used coconut sugar instead of cane sugar. For those sensitive to cane sugar or just wanting to try something new, this lovely cake is for you.
Coconut sugar is a darker sugar, so your cake and buttercream will come out a little darker in color than if you use cane sugar. Keep that in mind when you take a peek at your cake in the oven- it may look more done than it truly is. You are welcome to use cane sugar in this recipe, it will still turn out scrumptious.
Ingredients for the cake:
2 ½ cups flour (sifted)
1 ½ tsp baking powder
½ tsp baking soda
¾ tsp salt
1 cup butter (room temperature)
1 ½ cups coconut sugar
2 T lemon zest
1 cup milk
¼ cup lemon juice (roughly 3 lemons)
1 T vanilla extract
Ingredients for the filling:
2 cups blueberries
1 cup coconut sugar
1 T lemon juice
Ingredients for the buttercream:
4 cups powdered coconut sugar
1 cup butter (room temperature)
½ Tsp vanilla extract
1 cup blueberries (optional)
Before making your cakes, prepare the filling.
If you’re using fresh lemon juice, squeeze your lemons into a measuring cup and set aside. All 3 lemons should make a little over ¼ cups of juice, so you can use the extra in your filling. Hold onto at least 1 lemon before discarding it to use for zesting.
In a large saucepan on medium heat, add your blueberries, sugar, and tablespoon of lemon juice. Stir constantly to keep the sugar from burning. After 3 to 4 minutes, or when your blueberries have begun to soften, smash them into a pulp with a potato masher or the back of a wooden spoon. Cook them down until it thickens. You’ll know it’s ready when the bottom of your pan doesn’t immediately flood with blueberries after you swipe a spoon across it.
Transfer your blueberry filling into a jar or bowl and set it aside in the refrigerator to cool.
Now you can begin making your cake. Preheat your oven to 350°F and prepare two 8-inch cake pans by buttering them and lining the bottom with parchment paper. Set them aside.
If you’re not using cake flour, sift your flour. I find that transferring it between two mixing bowls using a sifter or fine mesh strainer works very well.
In a large mixing bowl, add your sifted flour, baking powder, baking soda, and salt. Whisk together and set aside.
Cut your butter into tablespoons and add it to another large mixing bowl. Whip with a hand mixer until fluffy. I find that cutting the butter makes it easier to cream and fluff.
Zest your reserved lemon into the butter, in addition to your sugar. Whip with your hand mixer until incorporated. Add in your eggs one at a time and whip until the mixture is smooth.
In a separate bowl, whisk together your milk and lemon juice.
Add ⅓ of your flour mixture into your butter mixture, then add ½ of your milk mixture. Mix with a hand mixer until just incorporated. Repeat until everything is combined.
Divide the batter into your prepared 8-inch baking pans.
Bake for 40 minutes and allow them to cool before assembling.
While your cakes are baking, you can start the buttercream.
Powdered coconut sugar can be difficult to find in the store, but you can make your own using a blender or food processor. Simply blend it until it becomes a fine powder and it will incorporate wonderfully into your buttercream.
In a large mixing bowl, add your butter. Whip it with a hand mixer until fluffy.
Add your powdered coconut sugar into the butter one cup at a time, mixing until just combined each time.
Once all your sugar has been added to the butter, add in your vanilla extract. Mix the mixture for another 3-5 minutes and set aside in the refrigerator to use later.
When your cakes have cooled completely, you can begin assembling and decorating your cake. Get your blueberry jam, buttercream, cakes, and fresh blueberries ready for assembly.
You can level your cakes if you choose, but I often save extra buttercream for the top of the cake and use it to create an even surface.
You will need a piping bag to apply your buttercream, or a careful hand and a spatula if you prefer not to use one.
On your first layer, pipe a thick ring of buttercream around the interior edges of your cake. Fill the center with ½ of your jam and spread it in an even layer. Put your second cake on top.
Pipe a generous layer of buttercream on the sides of your cake and smooth them out with a spatula, then add a generous layer of buttercream on the top. Go over it a second time to cover all the spots and smooth it out, as well as making the top an even surface.
Decorate the cake to your desire. I enjoy piping a ring around the outside edge and adding the remaining blueberry jam into the center to help keep it from slipping down the sides. Piling a layer of fresh blueberries on top works wonderfully as well.
Put it in the refrigerator to set for an hour or so, or serve immediately.