Dark Chocolate Mousse Cake
This triple Dark Chocolate Mousse Cake is decadent, yet surprising light. It's made with a super moist chocolate cake base, followed by a light and airy chocolate mousse (made without gelatin), and then topped with a rich chocolate ganache.
INGREDIENTS
Chocolate Cake
- 1 Cup (120g) All-Purpose Flour
- ½ Cup (42g) Dutch Cocoa Powder
- 1 Teaspoon Fine Espresso Powder (optional)
- ¾ Teaspoon Baking Powder
- ½ Teaspoon Baking Soda
- ¼ Teaspoon Fine Sea Salt
- ¾ Cup + 2 Tablespoons (175g) White Granulated Sugar
- ⅓ Cup + 1 Tablespoon (80g) Neutral Oil (avocado, vegetable, canola)
- ⅓ Cup (76g) Full-Fat Sour Cream room temp
- 1 Whole Large Egg room temp
- 1 Teaspoon Pure Vanilla Extract
- ½ Cup (113g) Boiling Water
Chocolate Mousse
- 1 ½ Cups (340g) Heavy Cream
- 1 Whole Large Egg + 1 Large Yolk
- ⅓ Cup (67g) White Granulated Sugar
- ¼ Cup (21g) Dutch Cocoa Powder
- 1 Teaspoon Fine Espresso Powder
- ⅛ Teaspoon Fine Sea Salt
- 6 Ounces (170g) Dark Chocolate
- 1 Teaspoon Pure Vanilla Extract
- 1 Cup (227g) Heavy Cream (to be whipped) cold
Chocolate Ganache
- 5 Ounces (141g) Dark Chocolate 60% to 70%
- ⅔ Cup (151g) Heavy Cream
Instructions
Chocolate Cake
- Preheat Oven & Prep Pan - Preheat oven to 350ºF (180ºC). Grease and line a 9-inch (23cm) springform pan with parchment paper.
- Combine Dry Ingredients - In a small mixing bowl, whisk together the flour, Dutch cocoa powder, fine espresso powder, baking powder, baking soda, and salt.1 Cup (120g) All-Purpose Flour½ Cup (42g) Dutch Cocoa Powder1 Teaspoon Fine Espresso Powder (optional) ¾ Teaspoon Baking Powder½ Teaspoon Baking Soda¼ Teaspoon Fine Sea Salt
- Combine Wet Ingredients - In a large bowl and using a hand whisk, whisk together sugar, oil, sour cream, egg and vanilla until well combined.¾ Cup + 2 Tablespoons (175g) White Granulated Sugar⅓ Cup + 1 Tablespoon (80g) Neutral Oil (avocado, vegetable, canola)⅓ Cup (76g) Full-Fat Sour Cream1 Whole Large Egg1 Teaspoon Pure Vanilla Extract
- Combine Dry & Wet Ingredients - Sift in the dry ingredients, ensuring the cocoa powder lumps are push through the sieve. Gently whisk the dry and wet ingredients together until nearly incorporated. The batter will be thick at this point and that's okay.
- Add Hot Water - Add boiling hot water and gently whisk until just combined. The batter will thin out a bit. Do not overmix.½ Cup (113g) Boiling Water
- Bake - Pour cake batter into your prepared pan and bake for 24 to 28 minutes or until an inserted toothpick comes out clean. Timing can vary on your oven, so keep an eye on it.
- Cool - Cool on a wire rack for 15 minutes, then remove the cake from the pan and let cool completely at room temperature or in the fridge.
Chocolate Mousse
- Combine Ingredients - In a small saucepan, and off heat, whisk together heavy cream, a whole egg, a yolk, sugar, cocoa powder, espresso powder, and salt until well combined.1 ½ Cups (340g) Heavy Cream1 Whole Large Egg + 1 Large Yolk⅓ Cup (67g) White Granulated Sugar¼ Cup (21g) Dutch Cocoa Powder1 Teaspoon Fine Espresso Powder⅛ Teaspoon Fine Sea Salt
- Cook - Over low heat, and whisking constantly, heat until the mixture reaches 170ºF (76ºC). It will take about 8 to 10 minutes.
- Add Chocolate - Off heat, add chocolate and vanilla and whisk until smooth and combined.6 Ounces (170g) Dark Chocolate 1 Teaspoon Pure Vanilla Extract
- Chill - Transfer chocolate mixture to a medium bowl and place a piece of plastic wrap directly on top to prevent a skin from forming. Chill the chocolate mousse mixture in the fridge for 1 to 1.5 hour, until thick and spreadable. If you forget and the chocolate mixture hardens, let it sit on the counter until it softens a bit.
- Prep Cake Pan - As the chocolate mousse is cooling, line the bottom of your springform pan with a fresh piece of parchment paper. If needed, level off the top of the cake with a serrated knife. Next, place cooled chocolate cake back into the springform pan. Wrap the sides of the cake with a 29-inch (74cm) long piece of acetate (cake collar). Tape the acetate together at the ends to prevent it from unraveling. You can also use parchment paper. Just lightly sprayed it with oil to make it easier to release the cake.
- Combine Whipped Cream & Cooled Chocolate Mixture - After 1 to 1.5 hours, remove the chocolate mixture from the fridge and give it a good mix. Once it has thickened into a spreadable consistency, whip your cream.In a large mixing bowl, and using a hand mixer, whip cold heavy cream until firm peaks. Do not overmix.1 Cup (227g) Heavy Cream (to be whipped)Then in 2 additions, gently fold the chocolate mixture and whipped cream together until there are no more white streaks. Do not overmix.
- Chill the Cake - Spread the chocolate mousse on top of the cake layer. Chill for at least 8 hours.
Chocolate Ganache
- When you're ready to serve, make the chocolate ganache. Place finely chopped chocolate from a bar or chocolate chips in a heatproof medium bowl. 5 Ounces (141g) Dark Chocolate 60% to 70%
- In a small saucepan, and over medium heat, bring heavy cream to a low simmer until it reaches about 185ºF (85ºC). Submerge hot cream over the chocolate and let stand untouched for 4 to 5 minutes. Using a silicone spatula, slowly stir until smooth and combined. If the chocolate hasn't completely melted, place the bowl of ganache over a small pot of simmering water. Heat until completely smooth.⅔ Cup (151g) Heavy Cream
- Remove the chilled cake from the fridge and unmold it from the pan. Peel off the acetate/parchment paper and then slide the cake onto a serving plate.
- Pour the chocolate ganache on top the cake and using an offset spatula, spread it to the edges. Before serving, you can place the cake back into the fridge for 10 to 15 minutes to let the ganache set. Slice and enjoy!!
Notes
Dutch-Process Cocoa Powder - Make sure to use Dutch-process Cocoa Powder and not natural cocoa powder for this recipe. Droste, Ghiradelli, Rodelle, and Hershey's Special Dark are all great Dutch cocoa powders that I have enjoyed using.
Cake Strip - Use a cake strip to create a flat cake. Soak it in cold water for about 15 minutes. Just before baking, wring out the excess water and then wrap it snuggly the around the pan. The damp cake strip will regulate the pan's temperature, preventing the edges from cooking faster than the center. You can also use a damp tea towel.
Cake Collar (acetate sheet) - Please note that a cake collar will give you cleaner sides. If you are using parchment paper, lightly spray it with oil to help the mousse release more easily.
Storage - Store covered in the fridge for up to 5 days.
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