Dark Chocolate Mousse Cake: A Luxurious Dessert.

This Dark Chocolate Mousse Cake is a masterpiece of textures, designed for the true chocolate purist.¹ It features two distinct layers: a dense, fudgy flourless chocolate cake base and a cloud-like, airy dark chocolate mousse topping.²Because it relies on high-quality cocoa solids rather than flour for its structure, it is naturally gluten-free and possesses an intense, sophisticated flavor.+1

The secret to this cake’s success is the temperature of the ingredients. By carefully folding whipped cream into a cooled chocolate ganache, you create a stable, velvety mousse that holds its shape perfectly when sliced.

Ingredients

For the most luxurious result, use a dark chocolate with at least 70% cocoa solids.³

The Flourless Base

Dark Chocolate: 120g, chopped.
Unsalted Butter: 60g.
Granulated Sugar: 100g.
Large Eggs: 2, room temperature.
Cocoa Powder: 1 tablespoon (unsweetened).

The Dark Chocolate Mousse

Dark Chocolate: 200g, finely chopped.
Heavy Whipping Cream: 400ml (divided: 100ml for the ganache, 300ml for whipping).
Granulated Sugar: 2 tablespoons.
Vanilla Extract: 1 teaspoon.
Espresso Powder: 1/2 teaspoon (optional, to intensify the chocolate).

Instructions

Step 1: Prepare the Base

Preheat your oven to 175°C. Grease an 8-inch (20cm) springform pan and line the bottom with parchment paper. Melt the 120g of chocolate and butter together until smooth. Whisk in the sugar, then the eggs one at a time. Sift in the cocoa powder and fold gently. Pour into the pan and bake for 18–20 minutes. The base will be thin and fudgy. Let it cool completely in the pan.

Step 2: Create the Ganache

Place the 200g of chopped chocolate in a heat-proof bowl. Heat 100ml of the heavy cream (and espresso powder, if using) until it just begins to simmer. Pour the hot cream over the chocolate. Let it sit for 2 minutes, then stir until glossy and smooth. Crucially, let this ganache cool to room temperature before proceeding.

Step 3: Whip the Cream

In a chilled bowl, whisk the remaining 300ml of heavy cream with the sugar and vanilla until medium-stiff peaks form.

Step 4: Fold and Assemble

Gently fold one-third of the whipped cream into the cooled ganache to lighten the mixture. Carefully fold in the remaining cream using a spatula, being mindful not to deflate the air. Pour the mousse over the cooled cake base in the springform pan. Smooth the top with an offset spatula.

Step 5: The Set

Refrigerate the cake for at least 6 hours, though overnight is ideal. This allows the cocoa butter to firm up, creating a clean, stable slice.

Flavor and Texture Notes

This cake offers a deeply immersive chocolate experience. The base is chewy and truffle-like, providing a sturdy foundation for the ethereal, melt-in-the-mouth mousse. The high cocoa percentage ensures a bittersweet finish that is rich but never cloying.⁴

Tips for Success

Temper the Ganache: If the ganache is too warm when you add the whipped cream, the mousse will collapse. If it is too cold, it will create lumps. It should feel barely lukewarm to the touch.
The Clean Release: Before opening the springform latch, run a thin knife dipped in hot water around the inside edge to ensure the mousse doesn’t tear.
Quality Matters: Since chocolate is the primary ingredient, avoid “compound” chocolate or chocolate chips; use high-quality baking bars for the smoothest texture.

FAQ

Question	Answer
Can I make this dairy-free?	Yes, you can substitute the butter and cream with high-fat coconut cream and a plant-based butter alternative.
How do I store it?	Keep it in the refrigerator in an airtight container for up to 3 days.
Can I freeze it?	Yes. This cake freezes beautifully for up to 2 months. Thaw in the fridge for 24 hours before serving.

Conclusion

The Dark Chocolate Mousse Cake is a celebration of chocolate in its purest forms. While it looks like it belongs in a high-end French bakery, the process is straightforward once you master the art of the gentle fold. It is the ultimate centerpiece for any formal dinner or special occasion.