Inspired by a French Fraisier cake, this delicious dessert features two layers of fluffy sponge cake, sandwiched with a luscious basil mousseline cream, tangy strawberry basil compote, and fresh strawberries. It’s the perfect cake for summer!

With the weather warming up and fresh strawberries in season, I knew I had to create recipe to celebrate summer strawberries. This strawberry basil sponge cake draws inspiration from the French Fraisier cake to create a light and fluffy dessert that is full of strawberry flavor and a refreshing hint of basil.

What is a Fraisier cake?

The Fraisier cake is a classic French dessert known for its elegant appearance and delicate flavors. Traditionally, it consists of layers of sponge cake, crème mousseline (pastry cream lightened with butter), and fresh strawberries. This strawberry basil sponge cake draws inspiration from this timeless dessert, infusing it with a unique twist of basil for an unforgettable taste. Typically Fraisier cakes will use a genoise sponge, which doesn’t have any leavening agents outside of whipped eggs. In this recipe, we’ll add some baking powder to help with the rise and create a more forgiving cake.

What makes this strawberry sandwich cake unique?

The combination of fresh strawberries and aromatic basil make for the perfect flavor combo. The cake uses a traditional fat-less sponge cake that is extra light and airy – a perfect complement to the rich and buttery basil mousseline cream. To pack home the flavor and keep the sponge from drying out, we add a layer of strawberry basil compote.

How to make a soft and fluffy sponge

The sponge is the base for this cake, so you’ll want it to be thick and fluffy! The sponge is leavened by whipping egg whites and folding back into the batter, and we add some baking powder as well to help the rise.

Tips for perfect sponge cake

This sponge cake is made by whisking egg yolks and whites separately, then folding them together with the dry ingredients. The key to a great sponge cake lies in a well-whipped meringue and a great folding technique

1. Separate the eggs carefully: Start with fresh eggs at room temperature. Separate the yolks from the whites, ensuring no traces of yolk mix with the whites. Even a small amount of yolk can hinder the egg whites from reaching their full volume.
2. Use a clean bowl and utensils: Any grease or residue in your mixing bowl or utensils can prevent the egg whites from whipping properly. Make sure they are thoroughly cleaned and dried before you begin.
3. Gradually add sugar: With the mixer still running, gradually add sugar to the whipped egg whites. Adding the sugar gradually allows it to dissolve and incorporate evenly, resulting in a stable foam.
4. Whip until stiff peaks form: Continue beating the egg whites and sugar until they reach stiff peaks. Stiff peaks hold their shape firmly when the beaters are lifted. No need to over-whip – once they hold their shape, they’re ready to be folded in. It’s okay if the tip of the meringue droops a little.
5. Gently fold in the ingredients: Start by folding the egg whites into the yolks. I do this in 3 parts. Then, sift the dry ingredients into the batter and fold in, again in 3 parts. Be careful not to overmix, as this can deflate the air you’ve incorporated. Doing it in separate parts helps get a more even distribution.
6. Bake immediately: Once the batter is mixed, transfer it to prepared baking pans and place them in the preheated oven right away. Delaying the baking process can cause the air bubbles to collapse, resulting in a denser cake.

By following these tips, you’ll achieve a soft and fluffy sponge cake with a tender crumb and a light texture. Whip those egg whites to perfection and enjoy the heavenly taste and delightful aroma of your strawberry basil sponge cake!

How to make a smooth mousseline cream

Mousseline cream is a variation of pastry cream enriched with butter, resulting in a lighter and silkier texture. I love using it as a cake filling because it tastes rich and flavorful without being too sweet. When testing the recipe, I made one variation where the mousseline cream was made with Italian meringue buttercream rather than straight butter. The texture was lighter, but as soon as the cake was chilled there wasn’t a big difference – as a result, I went with the butter-only variation since it’s significantly less work.

Tips for a flavorful basil pastry cream

Making pastry cream can feel intimidating, but with a few tips and tricks, you can achieve a smooth and luscious result. Here are some tips for making pastry cream:

1. Infuse the milk with basil for at least 30 min: We’ll start by heating the milk to a simmer and adding fresh basil leaves. Make sure it sits for at least 30 minutes so that the cream is full of basil flavor.
2. Temper the eggs: To prevent the eggs from curdling when combined with hot milk, temper them first. Gradually whisk a small amount of the hot milk into the beaten eggs and sugar mixture before returning it to the saucepan. This gradual process helps bring the eggs up to temperature without scrambling them.
3. Strain the mixture: To ensure a silky smooth consistency, strain the cooked pastry cream through a fine-mesh sieve. This step helps remove any lumps, basil chunks, and bits of cooked egg
4. Prevent a skin from forming: Pastry cream tends to develop a skin when it cools. To prevent this, place a layer of plastic wrap directly on the surface of the pastry cream before refrigerating. The plastic wrap prevents air from coming into contact with the cream, helping to maintain its smoothness.

Tips for incorporating the pastry cream and butter

1. Chill the pastry cream thoroughly: Make sure that the pastry cream chills to room temperature at least before adding to the butter. Otherwise, the butter may melt and you’ll be left with a slack mousseline cream
2. Ensure that the butter is softened but not melting: The butter should be soft enough to incorporate smoothly into the pastry cream, but it should not be melty. When you press a finger into it, it should leave an indent and be pliable.

Assembling the strawberry basil cake

Now it’s time to bring all the components together for a show-stopping presentation! Because the edges of this cake are unfrosted, it makes assembling more straightforward.

1. Evenly divide your sponge cake into 2 even layers. Brush both layers with the strawberry basil syrup.
2. Place one sponge cake layer on a serving plate.
3. Spread a thin layer of basil mousseline cream and pipe larger dollops around the edge of the cake
4. Spread a thin layer of strawberry basil compote and fill the center with diced fresh strawberries
5. Top with the second sponge cake
6. Decorate the top with the remaining mousseline cream and diced strawberries

I think the cake tastes best if you chill for a few hours to help the flavors meld together, but you can also serve immediately.

Other strawberry desserts to try

• Strawberry mochi muffins
• Strawberry cheesecake brioche buns
• Matcha strawberry cream bars

Ready to make this summer dessert cake? If you make this recipe, please let me know! I always love to see what my readers are baking. You can comment below or tag me on Instagram @halicopteraway.