If you adore decadent desserts that look as impressive as they taste, you are going to fall head over heels for this Chocolate Strawberry Mousse Cake Slice. This layered delight combines the rich depth of chocolate sponge with the light, fruity brightness of strawberry mousse, all topped off with a silky chocolate mousse layer. Each bite is a harmonious blend of textures and flavors that feels both indulgent and refreshing. Whether you’re treating yourself or impressing guests, the Chocolate Strawberry Mousse Cake Slice is pure dessert magic on a plate.

Chocolate Strawberry Mousse Cake Slice Recipe - Recipe Image

Ingredients You’ll Need

Getting your ingredients right is the secret to making a show-stopping Chocolate Strawberry Mousse Cake Slice. Each item plays a vital role: the cocoa and coffee deepen the sponge’s chocolate flavor, fresh strawberries bring natural sweetness and vibrant color, and gelatin ensures the mousse layers hold their light and airy texture beautifully.

All-purpose flour: Provides structure for the chocolate sponge to stay tender yet firm enough for layering.
Granulated sugar: Sweetens the cake and mousses to balance the intense chocolate and tangy strawberry flavors.
Cocoa powder: Adds rich chocolate intensity to the sponge cake base.
Baking powder and baking soda: Leaveners that give the sponge a soft, airy crumb.
Salt: Enhances all the flavors and keeps the sweetness from becoming one-note.
Eggs: Essential for structure and moisture in the cake layers.
Buttermilk: Tenderizes the sponge and adds subtle tang.
Vegetable oil: Keeps the cake moist without a heavy feel.
Vanilla extract: Brings warmth to both cake and mousse elements.
Hot water or brewed coffee: Intensifies the chocolate notes in the sponge.
Fresh strawberries: The star in the strawberry mousse, ensuring freshness and natural flavor.
Lemon juice: Brightens the strawberry puree for perfect balance.
Powdered gelatin: Gives the strawberry mousse a silky, set texture.
Heavy whipping cream: Adds lush creaminess to both mousses and the whipped topping.
Powdered sugar: Sweetens the whipped cream without graininess.
Semi-sweet chocolate and butter: Create a smooth, glossy base for the chocolate mousse layer.
Egg yolks and sugar: Whisked to add richness and subtle sweetness to the chocolate mousse.
Chocolate curls or shavings: Decorative and delicious finishing touch for garnish.
Fresh strawberries (for decoration): Adds vibrant color and freshness on top.
Whipped cream (optional): To embellish and complement each slice beautifully.

How to Make Chocolate Strawberry Mousse Cake Slice

Step 1: Bake the Chocolate Sponge Cake

This cake’s base is your classic chocolate sponge, made deeply flavorful by cocoa and enriched subtly with hot coffee or water. Start by whisking all your dry ingredients together for an even rise. Add the wet ingredients and mix until smooth; the batter should be slightly thin, which is perfect for a tender sponge. Baking it in a greased, lined pan ensures it comes out easily, and once it’s cooled, you’ll have a sturdy yet soft canvas to build your mousse layers on.

Step 2: Prepare the Strawberry Mousse

Making strawberry mousse is where this dessert gets its fresh and fruity personality. Puree ripe strawberries for a natural sweetness and color, then gently heat them with sugar and lemon juice to release those bright flavors. Gelatin is your best friend here—when bloomed properly and folded into the mixture, it creates a mousse that’s airy but still holds its shape. Whipping cream adds the necessary lightness, and chilling the mousse before assembly thickens it to perfection.

Step 3: Whip Up the Chocolate Mousse

The chocolate mousse layer is what makes this cake irresistible. Melted chocolate blended with butter creates luscious depth, while egg yolks and sugar add richness and silkiness. After whipping cream to soft peaks and folding it in gently, you get a mousse that feels like a rich cloud over the sponge. Ensure your chocolate mixture isn’t too hot when combining to keep the whipped cream fluffy and the texture light.

Step 4: Assemble the Cake Slices

Layering your creation is the best part. Start with the cooled chocolate sponge at the bottom of your mold or serving dish, then spread a smooth layer of chocolate mousse. Follow this with a thick, creamy strawberry mousse layer. Repeat if your dish allows for more layers. Chill the entire assembly for several hours until everything sets harmoniously. Once firm, slice into neat, elegant portions—the famous Chocolate Strawberry Mousse Cake Slice that’s ready to dazzle.

How to Serve Chocolate Strawberry Mousse Cake Slice

Garnishes

The finishing touches elevate the Chocolate Strawberry Mousse Cake Slice to something truly special. A swirl of whipped cream balances richness with lightness, while fresh halved strawberries add a pop of vibrant color and fresh fruitiness. Chocolate curls or shavings bring elegance and a delightful texture contrast that’s simply irresistible.

Side Dishes

While this cake slice is a showstopper on its own, pairing it with a cup of freshly brewed coffee or a light sparkling wine enhances the experience. Fresh berries or a small scoop of vanilla bean ice cream offer a refreshing side that complements the mousse’s creaminess without overpowering the delicate balance of flavors.

Creative Ways to Present

If you want to wow your guests, serve each Chocolate Strawberry Mousse Cake Slice on a stylish dessert plate with a drizzle of berry coulis or chocolate sauce. Add edible flowers or mint leaves for a pop of color and freshness. For a casual setting, present slices in clear glasses layered with extra mousse and fruit for an elegant parfait-style treat.

Make Ahead and Storage

Storing Leftovers

After enjoying your delicious slices, store any leftovers tightly covered in the fridge. They will stay fresh for up to three days, allowing the flavors to meld further and the mousse to maintain its creamy texture without drying out.

Freezing

The Chocolate Strawberry Mousse Cake Slice can be frozen, but with caution. Wrap slices individually in plastic wrap and then foil to prevent freezer burn. Thaw overnight in the fridge before serving. Note that the mousse texture might soften slightly after freezing but will still be deliciously enjoyable.

Reheating

Since this is a chilled mousse cake, reheating is not recommended. Serve it directly from the fridge or at room temperature to enjoy the layers in their perfect, creamy state.

FAQs

Can I use frozen strawberries for the mousse?

You absolutely can! Just make sure to thaw and drain them well to avoid excess liquid that could affect the mousse’s texture. Using fresh strawberries is ideal for the brightest flavor and color.

Is it safe to use raw egg yolks in the chocolate mousse?

If you’re concerned about consuming raw egg yolks, use pasteurized eggs or consult trusted recipes that cook the egg yolks gently to a safe temperature. Otherwise, the mousse is best enjoyed fresh due to the raw egg content.

Can this cake be made in advance?

Yes! The Chocolate Strawberry Mousse Cake Slice actually benefits from making ahead. Chilling overnight allows the mousse layers to set perfectly and the flavors to meld wonderfully.

How do I get clean slices when cutting the mousse cake?

Use a sharp knife dipped in hot water and wiped dry before each cut. This helps the knife glide smoothly without dragging the mousse layers and keeps edges neat.

Can I substitute gelatin with agar-agar?

Agar-agar can be used as a vegetarian alternative, but it sets differently. Make sure to follow instructions carefully as it sets firmer and quicker than gelatin. The texture might be slightly less creamy but still delicious.

Final Thoughts

There is something truly special about a dessert that marries the luxurious flavors of chocolate with the fresh brightness of strawberries so effortlessly. This Chocolate Strawberry Mousse Cake Slice is one of those gems that makes celebrations, or even ordinary days, feel extraordinary. I wholeheartedly encourage you to try making it—it’s a wonderful way to treat yourself and your loved ones to a slice of happiness that’s as pretty as it is delicious.