Cake,  Layer Cake

Vanilla Cake with Blackberry Buttercream

Oh man. Sometimes you stumble upon something simple that is just AMAZING. This…THIS is one of those times.

Vanilla Cake with Blackberry Buttercream. 😀

vanilla cake blackberry buttercreamYou may remember that I made a Chocolate Cake with Dark Chocolate Italian Buttercream for my oldest son’s (James’) 11th birthday. He’s a chocolate everything guy when it comes to his birthday cake (and who can blame him?).

My daughter (Katie), however, chooses vanilla cake with vanilla frosting every year, as she must be the opposite of her brother in all things. My husband and son will try to talk her into chocolate, but it’s a no-go. Vanilla-vanilla is what she wants.

vanilla cake blackberry buttercreamI decided to make a new recipe, which I often do, and the vanilla cake was seriously the BEST I ever made. That said…the resulting cake (with marshmallow buttercream) was a gaudy disaster once my nine-year-old daughter got done with her cake requests. Covered *completely* in multi-colored sprinkles, topped with swirls of buttercream, royal icing flowers, and a gold glittery “9”…let’s just say it wasn’t exactly blog-worthy. (She loved it, though!)

vanilla cake blackberry buttercreamBut that cake! The vanilla cake was in my head. I knew that I needed to make it again. Maybe a different flavor combo this time. While at the peach orchard with the fam, I saw the HUGEST most beautiful blackberries I’d ever seen. I immediately knew what to do with them!

Just in case you’re wondering…it’s totally acceptable to make this blackberry buttercream and then just eat it with a spoon. You’re welcome.

vanilla cake blackberry buttercreamA few things worth mentioning regarding ingredients and hardware:

– The cake flour and coconut oil help lend the cake it’s super soft and fluffy texture. I don’t suggest substitutions for these! The buttermilk, however, can be substituted if you don’t have it on-hand (instructions in the recipe notes).

– The recipe is for an 8″ triple-layer cake. If you prefer to make a 6″ triple-layer cake, I have details on that in the recipe notes.

– To ensure I have the same amount of batter in each pan, I use my kitchen scale (link [here]) and weigh the pans. It’s hard to eyeball the amount when you’re using three pans, especially if you don’t have three and you’re baking the cake layers individually.

– I use cake strips on my pans when making a layer cake, since they help the cake bake up flatter (see: easier assembly). If you’re in the market for them, you can find them [here].

– The only sprinkles on this cake are edible flowers…*heart eyes*

vanilla cake blackberry buttercreamPlease, please treat yourself to this cake. I can’t wait to make it again with a different buttercream. Or, you know, just eat it warm from the pan. Either way I’m a happy girl.

Other posts you may like:

Blackberry Vanilla Pies

Vanilla Cake with Berry Buttercream

Blackberry Cream Pie

Sangria Cake

Blackberry Lemon Meringue Pie

Blackberry Cake

Blackberry Lavender Brownie Pie

Vanilla Cake with Blackberry Buttercream

This vanilla cake is amazing--soft, fluffy, and flavorful. With the addition of blackberry Swiss meringue buttercream, it's like a dream!
Course Dessert
Cuisine Cakes
Servings 1 8" triple-layer cake


Vanilla Cake:

  • 4 cups cake flour (see note)
  • 1 cup unsalted butter, soft but still cool (2 sticks)
  • cup virgin coconut oil, solid but creamy (see note)
  • 2 cups sugar
  • tsp baking powder
  • 1 tsp baking soda
  • ¼ tsp salt
  • 1 cup egg whites (from about 6 eggs)
  • 1 Tbsp vanilla bean paste (see note)
  • 2 cups buttermilk (can substitute, see note)

Blackberry Reduction:

  • 12 oz blackberries (fresh or frozen)
  • 1 Tbsp sugar
  • 1 Tbsp lime juice

Blackberry Buttercream:

  • 6 egg whites
  • cups sugar
  • cups unsalted butter, softened (3 sticks)
  • 1 tsp vanilla extract
  • 2 Tbsp blackberry reduction


For Cake:

  • Preheat oven to 325°F. Grease three 8" cake pans and set aside (see note).
  • In the bowl of a stand mixer, combine butter, coconut oil, sugar, baking powder, baking soda, and salt. Mix until light and fluffy. Scrape down the sides of the bowl.
  • With the mixer running on low, add the egg whites one at a time. Add vanilla bean paste (see note) and mix to combine.
  • With the mixer running on low, alternate additions of flour and buttermilk. Add 1/3 of the flour, followed by 1/3 of the buttermilk. Repeat for remaining flour and buttermilk, allowing each addition to incorporate before adding the next.
  • Divide the batter between the prepared pans (see note). Affix cake strips, if using (see note).
  • Bake for about 40 minutes, turning the cakes around at the halfway point to help ensure an even bake. A toothpick inserted in the center of the cake should come out clean. Allow the cakes to cool completely on a wire rack.

For Blackberry Reduction:

  • Combine blackberries, sugar, and lemon juice in a medium saucepan. Over medium heat, cook mixture until juices bubble and berries are soft.
  • Using a fine mesh strainer, strain the mixture, discarding the seeds and pulp. Return the juice to the pan.
  • Over medium heat, cook blackberry juice until reduced to about 2 tablespoons, about 10 minutes. Let cool completely.

For Buttercream:

  • Combine egg whites and sugar in the bowl of a stand mixer and whisk to combine. Place the bowl over a pan of simmering water, taking care that the water doesn't touch the bowl. Cook mixture on medium heat until it reaches 160°F.
  • Once the mixture reaches temperature, carefully transfer the bowl to the mixer. Using the whisk attachment, beat on high speed until white, glossy, and bowl is no longer warm to the touch, about 10 minutes.
  • With the mixer running on low speed, add butter a few pieces at a time. Allow each addition to incorporate before adding the next. Once all butter is incorporated, add vanilla extract and whip until smooth, another 3-5 minutes.
  • Add blackberry reduction and whip until fully combined.
  • Frost the cooled cakes with buttercream. Top with fresh blackberries, if desired.


Note on cake flour and coconut oil: These ingredients help lend the cake it's super soft and fluffy texture. I don't suggest substitutions for these!
Note on buttermilk: If you don't have buttermilk, you can make a quick substitution with milk (2% milkfat or greater) and vinegar or lemon juice. For this recipe, pour 2 tablespoons lemon juice or vinegar into a liquid measure, then add enough milk to come up to the 2 cup line. Let sit for 5 minutes, then it's ready for use!
Note on vanilla bean paste: You know me, it's in everything! Delicious and more economical than whole vanilla beans, this ingredient is my go-to for an extra punch of flavor. You can find it online [here]. If you prefer to substitute, you can use an equal measure of vanilla extract.
Note on cake pans: This recipe is for an 8" triple-layer cake. If you don't have three pans, the batter will still be good at room temperature for about three hours if you need to bake them individually. See note on using a kitchen scale--it's much easier to divide the batter equally when you have one!
Also...I've made this recipe in both 8" pans and 6" pans. If you prefer to make an 6" triple-layer cake, make half the cake recipe as written here. Bake time will be about 30 minutes. You'll need about 2/3 this buttercream recipe for a 6" cake. If you're looking to get some 6" pans for yourself, these are the ones that I use [here]. 
Note on kitchen scale: To ensure I have the same amount of batter in each pan, I use my kitchen scale (link [here]) and weigh the pans. It's hard to eyeball the amount when you're using three pans, especially if you don't have three and you're baking the cake layers individually.
Note on cake strips: I use cake strips on my pans when making a layer cake, since they help the cake bake up flatter (see: easier assembly). If you’re in the market for them, you can find them [here].
Tried this recipe?I'd love to hear all about it! Leave a review below, then snap a pic and tag me on Instagram!
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