Name: Dark Chocolate Mousse Cake
Cook time: 25 min
Total time: 25 min
Yield: 10 slices
Cuisine: American
Ingredients: 160 grams all-purpose flour; 224 grams granulated sugar; 21 grams dutch process cocoa powder; 21 grams black cocoa powder; 1 tsp baking powder; 0.25 tsp salt; 150 grams whole milk; 100 grams neutral oil; 2 eggs; 1 tsp vanilla extract; 75 grams freshly brewed hot espresso; 227 grams dark chocolate; 283 grams heavy cream; 1 egg; 1 tsp vanilla extract; 0.25 tsp salt

Everything you could ever want in a chocolate cake is right here in this dark chocolate mousse cake! It consists of four layers of incredibly moist chocolate sponge, decadent dark chocolate mousse, and silky dark chocolate ganache. It’s a chocolate on chocolate dessert yet it isn’t overwhelmingly rich, it’s just the right amount of decadence to satisfy that chocolate craving.

Dessert

25 m

American

Sloane’s Table

March 11, 2026

Atsloanestable.com

From the Cook

1/4

Dark Chocolate Mousse Cake

Sloane’s Table Verified

Atsloanestable.com

Ingredients

Warning0 allergens identified

Dark Chocolate Mousse Cake

Chocolate Cake

160 grams all-purpose flour

224 grams granulated sugar

21 grams dutch process cocoa powder

21 grams black cocoa powder

1 tsp baking powder

¼ tsp salt

150 grams whole milk

100 grams neutral oil

2 eggs

1 tsp vanilla extract

75 grams freshly brewed hot espresso

Dark Chocolate Mousse

227 grams dark chocolate

283 grams heavy cream

1 egg

1 tsp vanilla extract

¼ tsp salt

Instructions

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Chocolate Cake

Preheat the oven to 350 degrees F and line a 9" square pan with parchment paper.

Soak cake strips in ice water.

In a medium bowl, whisk together the flour, sugar, cocoa powders, baking powder, and salt. Set aside.

In a large bowl, whisk together the milk, oil, eggs, and vanilla.

Add the dry ingredients to the wet and whisk until just combined.

Lastly, whisk in the hot coffee until fully combined.

Pour the cake batter into the prepared pan and wrap the soaked cake strips around the outside of the pan. Bake for about 25 minutes or until a toothpick inserted comes out clean the cake pulls away from the sides of the pan.

Allow the cake to cool in the pan completely. Cover with plastic wrap and set aside until ready to assemble.

Dark Chocolate Mousse

In a medium bowl, add the chocolate and set aside.

In a small saucepan, bring 170g (¾ cup) heavy cream to a simmer (or about 190 degrees F), then pour over the chocolate and mix until smooth.

Whisk in the egg, vanilla, and salt until fully combined.

In a separate small bowl, add the remaining 113g (½ cup) heavy cream and use an electric mixer to beat until stiff peaks form.

Add the whipped cream to the chocolate mixture and gently fold with a rubber spatula until fully combined.

Pour into a shallow dish and press plastic wrap up against the surface and chill for at least one hour.

Assemble

Line a pullman pan with parchment paper.

Cut the cooled cake in half, and each half into two layers, giving 4 layers measuring roughly 9x5. You may need to trim the sides to make them fit in the pan.

Add the first cake layer to the bottom of the pan and top with ⅓ of the mousse. I used a 3 tablespoon cookie scoop and added 4 scoops to each layer.

Repeat with the remaining cake layers and mousse. Set aside.

Dark Chocolate Ganache

In a small saucepan, bring the heavy cream to a simmer (or about 190 degrees F), then remove from heat, add the chocolate, and mix until smooth.

Pour the warm ganache over the assembled cake and spread into an even layer.

Place the cake in the fridge uncovered and chill for at least two hours before serving.

Nutrition

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Tips & Tricks (5)

Espresso Enhancement 🍫
Add freshly brewed hot espresso to your melted dark chocolate while it's still warm to deepen the chocolate flavor and reduce any bitterness without making it taste like coffee.
Mousse Aeration Secret 🫧
Whip heavy cream to soft peaks and fold gently into your chocolate mixture in two additions to maximize air incorporation, creating an impossibly light and silky mousse texture.
Sponge Cake Moisture Trick 💧
Brush each layer of cooled chocolate sponge with cooled espresso or simple syrup before adding mousse to keep the cake incredibly moist and prevent it from drying out between layers.
Dutch vs Black Cocoa Balance ⚖️
Use Dutch process cocoa for the cake layers (milder, earthier flavor) and black cocoa for dusting or ganache (intense, bold notes) to layer chocolate complexity without overwhelming richness.
Ganache Timing for Perfection ⏱️
Pour ganache over the cake when it's still warm but the mousse filling is completely chilled and set, allowing it to create a glossy seal without melting the delicate mousse layers.