I turned 29 this summer and I wanted to make my own birthday cake. Having a July birthday means blackberries are in prime season. Having a garden means lavender is abundant. I combined the two for this delicious blackberry lavender birthday cake!

It’s pretty heavily inspired by Half Baked Harvest‘s version, but to be honest I found myself tweaking every little thing that I think this turned out pretty differently. The flavors are similar, but my cake was more reminiscent of the kind we make at Baked on 8th.

The key to a fluffy homemade cake is, in my opinion, cake flour! Swan’s brand is what I always go for because it’s the only one sold in normal grocery stores. If you don’t have access to this or don’t have it on hand, you can use all purpose flour – I have a note in the recipe.

“Torting” a birthday cake means making more layers out of what you have. I baked two layers and “torted” them to make four! This can sometimes be a little difficult and is made much easier by having a long sturdy knife. I suggest doing this once your cake is completely cooled, before you pop it in the freezer.

Icing a frozen cake will also make your life much easier to get those smooth edges!

The cake rounds for this blackberry lavender birthday cake can be made several days ahead and kept wrapped in the freezer.

The blackberry lavender filling can be made 1-2 days ahead and kept in the fridge.

The buttercream is easiest to work with if made day of.

If you need a gluten free dessert to serve alongside this with similar ingredients, I’d highly recommend either this gluten free buttermilk pound cake!

Cake Ingredients:

• 1 cup neutral oil
• 1/2 cup full fat sour cream
• 3 large eggs
• 2 cups cane sugar
• 1 tbsp vanilla
• 1 1/2 cups buttermilk (or 1 1/2 cups whole milk + 1 tbsp lemon juice)
• Zest of one lime or lemon
• 4 cups cake flour (or 3 3/4 cup all purpose flour)
• 1 tsp baking soda
• 1 tsp baking powder
• one tsp kosher or sea salt

Cake Instructions:

Preheat oven to 350 degrees F. Combine the oil, sour cream, eggs, sugar, vanilla, zest, and buttermilk in a stand mixer or in a bowl with an electric hand mixer. Mix well until eggs are fully incorporated. Scrape the bowl if necessary. Combine the cake flour, soda, powder, and salt in a bowl. Add to the wet and mix until just combined.

Distribute the cake mix equally between two greased 8 inch cake pans. Bake for about 40-50 minutes, until a toothpick comes out clean. Check at the 40 minute mark to be sure not to overbake them.

Allow to cool enough to handle, then remove from cake pans and allow to fully cool on a wire rack.

“Tort” the cakes by carefully slicing each layer into two thinner layers (optional!). Wrap them in plastic wrap and place in the freezer.

Blackberry Lavender Filling Ingredients:

• 3 small containers (6oz) blackberries
• 1 tablespoon dried lavender (find this in the spice aisle)
• 1/2 cup maple syrup or honey
• Pinch of salt

Blackberry Lavender Filling Instructions:

Add all ingredients to a small sauce pot and bring to a boil. Use a potato masher or a fork to mash down all of the berries. Reduce to low-medium and cook for 10-15 minutes, stirring often to avoid burning, until it has reduced and thickened to your liking.

I really hate blackberry seeds so I put this mixture through a sieve. It took a long time to really get all of the filling separated from the seeds, but in my opinion it was worth it! This step is optional.

White Chocolate Buttercream Ingredients:

• 3 sticks salted butter, room temperature
• 2 1/2 cups powdered sugar
• 1 tablespoon vanilla extract
• 1/4 cup heavy cream
• about 8 oz white chocolate, melted and slightly cooled (I used two Lindt brand white chocolate bars)

White Chocolate Buttercream Instructions:

In a stand mixer with the paddle attachment, whip the butter for 30 seconds. Scrape down the sides and slowly add in the powdered sugar 1/2 cup at a time, scraping as necessary. Turn the mixer to medium speed and add in the vanilla and heavy cream. Whip for 1 minute.

Stream in the white chocolate and whip until fully incorporated.

Now it’s time to make your cake! Place one layer down on a cake board. Add a little buttercream, a little filling, then the next layer. Continue to do this until you’ve used all layers and filling.

Ice the sides and top of the cake. Add a little filling around the sides if desired. I added a white chocolate drip as well!

Add sprinkles and flowers if you wish.

Print Recipe

Blackberry Lavender Birthday Cake

This birthday cake has a blackberry lavender filling and a white chocolate homemade buttercream that will make any summer birthday person happy!

Course: Dessert

Cuisine: American

Keyword: Birthday Cake, Cake, Layer Cake, Summer

Servings: 20 servings

Ingredients

Cake Ingredients

• 1 cup neutral oil
• 1/2 cup full fat sour cream
• 3 large eggs
• 2 cup cane sugar
• 1 tbsp vanilla extract
• 1 1/2 cup buttermilk or 1 1/2 cup whole milk + 1 tbsp lemon juice
• zest of one lime or lemon
• 4 cups cake flour or 3 3/4 cup all purpose flour
• 1 tsp baking soda
• 1 tsp baking powder
• 1 tsp kosher or sea salt

Blackberry Lavender Filling Ingredients

• 3 6oz containers blackberries
• 1 tbsp dried lavender
• 1/2 cup maple syrup or honey
• pinch of salt

White Chocolate Buttercream

• 3 sticks salted butter room temperature
• 2 1/2 cups powdered sugar
• 1 tbsp vanilla extract
• 1/4 cup heavy cream
• 8 oz white chocolate, melted and cooled

Instructions

Cake Baking Instructions:

• Preheat oven to 350 degrees F.
• Combine the oil, sour cream, eggs, sugar, vanilla, zest, and buttermilk in a stand mixer or in a bowl with an electric hand mixer.
• Mix well until eggs are fully incorporated. Scrape the bowl if necessary.
• Combine the cake flour, soda, powder, and salt in a bowl. Add to the wet and mix until just combined.
• Distribute the cake mix equally between two greased 8 inch cake pans. Bake for about 40-50 minutes, until a toothpick comes out clean. Check at the 40 minute mark to be sure not to overbake them.
• Allow to cool enough to handle, then remove from cake pans and allow to fully cool on a wire rack.
• "Tort" the cakes by carefully slicing each layer into two thinner layers (optional!). Wrap them in plastic wrap and place in the freezer.

Blackberry Lavender Filling Instructions:

• Add all ingredients to a small sauce pot and bring to a boil. Use a potato masher or a fork to mash down all of the berries. Reduce to low-medium and cook for 10-15 minutes, stirring often to avoid burning, until it has reduced and thickened to your liking.
• I really hate blackberry seeds so I put this mixture through a sieve. It took a long time to really get all of the filling separated from the seeds, but in my opinion it was worth it! This step is optional.

White Chocolate Buttercream Instructions:

• In a stand mixer with the paddle attachment, whip the butter for 30 seconds.
• Scrape down the sides and slowly add in the powdered sugar 1/2 cup at a time, scraping as necessary.
• Turn the mixer to medium speed and add in the vanilla and heavy cream. Whip for 1 minute.
• Stream in the white chocolate and whip until fully incorporated.

Assembly:

• Place one layer on a cake board and add buttercream, then 1/3 of the filling.
• Repeat steps until all 4 layers are together.
• Ice the sides and the top. Add some of the leftover filling if desired.
• Add sprinkles, flowers, and candles!