08/30/2026
Wait until you see the three chocolate layers
The Triple Chocolate Mousse Cake With Three Silky Chocolate Layers
This decadent homemade chocolate cake stacks a tender cocoa base, rich chocolate fudge, and two cloud-like mousse layers. 🍫✨ The final white chocolate mousse is unbelievably smooth, creating a creamy contrast against the deep chocolate layers.
Servings: 10
Ingredients
Chocolate Cake
¾ cup (92g) all-purpose flour
¼ cup (29g) Dutch-processed cocoa powder (sifted)
¾ teaspoon baking soda
¼ teaspoon salt
3 tablespoons (42g) unsalted butter (melted)
3 tablespoons (45ml) vegetable oil
½ cup (112g) packed light brown sugar
½ teaspoon vanilla extract
1 large egg white
2 tablespoons (29g) sour cream
3 tablespoons (45ml) milk
⅓ cup (80ml) hot water or coffee
Chocolate Fudge
6 ounces (170g) semi sweet chocolate chips
2 tablespoons (30ml) light corn syrup
½ teaspoon vanilla extract
½ cup (120ml) heavy whipping cream
Chocolate Mousse
4 large egg yolks
¼ cup (52g) sugar
1 ¾ cups (420ml) heavy whipping cream (cold, divided)
8 ounces (227g) semi sweet chocolate chips
¾ cup (86g) powdered sugar
White Chocolate Mousse
¾ teaspoon agar-agar powder
1 ½ tablespoons (23ml) water
9 ounces (255g) white chocolate chips
1 ¾ cups (420ml) heavy whipping cream (cold, divided)
⅓ cup (38g) powdered sugar
Toppings
Chocolate curls, optional
Cocoa powder, for dusting, optional
How to make it
Line the bottom of an 8-inch cake pan with parchment paper and grease the sides. Preheat the oven to 350°F (180°C).
Whisk together the flour, cocoa powder, baking soda, and salt in a medium bowl.
In a large bowl, mix the melted butter, vegetable oil, brown sugar, and vanilla until combined.
Mix in the egg white and sour cream, then add the milk and mix until combined.
Add the dry ingredients to the wet mixture and mix just until combined. Do not overmix.
Add the hot water and mix until incorporated.
Pour the batter into the prepared pan and bake for 18–22 minutes, or until a toothpick comes out clean.
Let the cake cool for 3–4 minutes, then turn it onto a cooling rack and cool completely.
Prepare a cake collar or line a springform pan with parchment paper extending about 2 inches above the top. Cut the dome from the cake and place the cake in the prepared pan or collar.
For the fudge layer, combine the chocolate chips, corn syrup, and vanilla in a heatproof bowl.
Heat the heavy whipping cream until it just begins to boil. Pour it over the chocolate, cover, and let stand for 3–5 minutes.
Whisk the mixture until smooth, then spread it evenly over the cake. Refrigerate for about 1 hour, until firm.
For the chocolate mousse, whisk the egg yolks, sugar, and ½ cup (120ml) heavy whipping cream together in the top of a double boiler.
Cook over simmering water, whisking constantly, until the mixture thickens, lightens, increases in volume, and reaches 160°F (71°C), about 7–10 minutes. Do not boil.
Melt the chocolate chips in short 10–15 second microwave intervals, stirring between each, until smooth.
Whisk the warm egg mixture into the melted chocolate until smooth, then let it cool to about room temperature.
Whip the remaining 1 ¼ cups (300ml) heavy whipping cream with the powdered sugar until stiff peaks form.
Fold about ¼ cup of whipped cream into the chocolate mixture. Then fold about ¼ of the chocolate mixture into the whipped cream before gently incorporating the remaining chocolate mixture.
Spread the chocolate mousse evenly over the fudge layer and refrigerate for about 1 hour.
For the white chocolate mousse, whisk the agar-agar powder into the water.
Place the white chocolate chips in a medium glass bowl.
Heat ½ cup (120ml) of the heavy cream until boiling. Add the agar-agar mixture and whisk while bringing the cream back to a brief simmer to activate the agar.
Pour the hot cream over the white chocolate, cover, and let stand for 3–5 minutes. Whisk until completely smooth. If needed, microwave in 10–15 second intervals, stirring between each, until melted.
Let the white chocolate mixture cool to about room temperature.
Whip the remaining 1 ¼ cups (300ml) heavy cream with the powdered sugar at high speed until stiff peaks form.
Gently fold one-third of the cooled white chocolate mixture into the whipped cream. Repeat with the second third, then fold in the remaining mixture until fully combined.
Spread the white chocolate mousse evenly over the chocolate mousse.
Refrigerate until completely firm, at least 3–4 hours.
Remove the cake from the pan or take off the cake collar. Smooth the sides with an offset spatula if needed, then transfer to a serving plate.
Finish with chocolate curls and a dusting of cocoa powder.
Keep refrigerated and well covered until ready to serve. Best eaten within 4–5 days.
Three layers of chocolate make this the kind of cake that turns an ordinary dessert table into something unforgettable.