Vanilla Cake with Strawberry, Fig, & Brown Butter Tonka Bean
Classic vanilla bean olive oil sponge brushed with vanilla bean cake soak, filled with strawberry & fig jam, and frosted in a brown butter tonka bean American buttercream. Dyed blue naturally.
Hi, everyone! This cake was developed and executed for a friend’s baby shower last year. Apart from it being made for someone I care about, this cake was also my first viral TikTok and helped boost my work significantly. This cake holds a very special place in my heart!
The base of this cake is a basic Vanilla Bean Olive Oil Sponge. This one of my favorite cake bases that works with almost all fillings and frostings. It is my go-to vanilla cake for a reason!
The filling of this cake is a strawberry and fig jam. When I made this cake, I was unable to find fresh figs, so I made a strawberry jam with fresh berries and added store-bought fig jam. This works extremely well and produces a lovely, fresh, homespun flavor despite the jarred component. Use a fig jam you love!
The star of the show for this cake is the strikingly blue buttercream. Because I don’t use any artificial colorings in my kitchen, I had to do a bit of research to find something that could elicit a true blue. I ended up using Kos’ Blue Spirulina. Unlike normal green spirulina, this spirulina is entirely odorless and tasteless (I promise). This powder whipped into the buttercream perfectly with no clumping. Tonka bean is a delicious extract ingredient that pairs beautifully with brown butter due to its nutty undertones. I had to order the extract online, but if you are unable to obtain tonka bean I’ve listed my suggested substitutions below!
This cake was commissioned to feed a large party (20), so you may want to cut the recipe a bit if you are not looking for a crowd-sized bake. As always, I’d love to hear from you! Happy baking!
Vanilla Cake with Strawberry, Fig, & Brown Butter Tonka Bean
Makes 1 8-inch double tier cake
Ingredients:
For the cake:
2 batches Vanilla Bean Olive Oil Cake, baked in 2 8-inch cake tins
For the cake soak:
1/2 cup water
100g granulated sugar
1 tbsp vanilla extract
For the jam:
1lb fresh strawberries, washed, trimmed, and halved
100g granulated sugar
2 tablespoons lemon juice
Pinch of salt
1 cup store-bought fig jam
For the buttercream:
450g unsalted butter, softened
960g powdered sugar, sifted
4-6 tablespoons heavy cream or whole milk
2 tablespoons vanilla extract
1 tablespoon tonka bean extract OR 1/2 teaspoon almond extract + additional tablespoon vanilla extract
Pinch of salt
4-6 tablespoons Kos Blue Spirulina, depending on your color preference
Method:
For the cake:
Bake the cake according to the written instructions. Cool completely before assembling.
For the cake soak:
Combine all ingredients in a heatproof bowl or mug.
Microwave for 1-2 minutes or until sugar has completely dissolved.
Set aside in the fridge until ready to use. (You can also make this in a small saucepan on the stovetop but I’ve found this method to be faster and easier with an identical result.)
For the jam:
In a large saucepan over high heat, combine all ingredients for the jam except the fig jam.
Bring this mixture to a boil, then reduce the heat to a simmer.
Continue to simmer the strawberries until they’re soft and broken down, about 20 minutes.
At this point, add the fig jam. Stir to combine.
Bring the mixture back up to a boil then reduce to a simmer for an additional 20 minutes.
Remove the jam from the heat and allow to cool entirely before assembling.
For the buttercream:
In a small saucepan over medium heat, melt half of the butter (225g), stirring frequently. The butter will foam. Continue stirring, ensuring there are no milk solids sticking to the bottom of the pan.
After the foam begins to settle, you will notice the milk solids toasting and beginning to smell nutty. Continue stirring and pay close attention as the butter can quickly go from browned to burnt.
Once the milk solids are a deep amber color, remove the butter from the heat and pour it into a large heat-proof mixing bowl. Allow the butter to come to room temperature before proceeding with the recipe.
In the bowl or your stand mixer (or large mixing bowl with your hand mixer), combine the browned butter and the rest of your softened butter. Beat the softened butter until light and fluffy (1-3 minutes).
Add half of the powdered sugar and beat on low speed until incorporated before turning up the speed and beating on high until combined. Repeat with the rest of the powdered sugar.
Assess the thickness of the buttercream and adjust with the heavy cream/milk/, one tablespoon at a time until your desired consistency is achieved. If you add too much liquid, add more powdered sugar, one tablespoon at a time, to thicken.
After you are satisfied with the viscosity of your buttercream, add the salt, vanilla, tonka bean and spirulina. Set aside at room temperature until ready to assemble.
Assembly:
Place your first layer of cake on your serving plate or cake board.
Brush generously with your cooled cake soak. Let sit for 1-2 minutes.
Add a scoop of your buttercream and spread evenly across your layer of cake. Create a dam around the outside rim of the cake layer by either piping or indenting the buttercream with an offset spatula. The dam is essential to keep the jam from spilling out the sides (unless that is what you are looking for aesthetically).
Fill the dam with your jam, spreading evenly.
Add your final cake layer.
Brush the cake layer with your cake soak and let sit for 1-2 minutes.
Add a large scoop of buttercream and thinly coat the entire cake as evenly as possible to create a crumb coat.
Place your thinly frosted cake in the refrigerator for 15 minutes, or until the frosting has hardened.
Once the crumb coat is solid, this is where you can get creative! I chose to keep the sides naked (at my friend’s request) and top the cake with some simple piping work.
Garnish your cake as desired and enjoy :)