Video
Chocolate Mousse Cake
My Chocolate Mousse Cake is outrageously decadent and delicious with rich, moist chocolate cake topped with a thick layer of dark chocolate mousse. As decadent as it is, it is also so light and airy. The best part is how easy this recipe is with a simple one bowl cake batter and no fuss chocolate mousse that doesn't contain any raw egg.
Ingredients
Chocolate Cake Batter:
- ⅔ cup (95g) all-purpose flour
- ⅓ cup (28g) cocoa powder (I prefer this one)
- ½ teaspoon baking powder
- ¼ teaspoon baking soda
- ¾ cup (150g) granulated sugar
- ¼ teaspoon salt
- ¼ cup (60ml) sunflower oil
- 1 large egg, lightly beaten
- ¼ cup (60ml) full fat sour cream
- ⅓ cup (80ml) warm milk
- 1 teaspoon (5ml) pure vanilla extract
Chocolate Mousse:
- 5 oz (142g) bittersweet chocolate (70% cocoa), finely chopped
- 2 oz (56g) milk chocolate, finely chopped
- ⅔ cup (150ml) whole milk
- 3 large egg yolks
- ⅓ cup (65g) granulated sugar
- pinch of salt
- 1 ¼ cups (300ml) cold heavy 35% whipping cream
NOTE: for best results, use a kitchen scale to weigh the ingredients.
Instructions
- Preheat the oven to 350°F. Line an 8x8-inch metal baking pan with parchment paper leaving a 2-inch overhang at each side so you can easily remove the cake afterwards.
- Make the cake. Sift flour, cocoa powder, baking powder and baking soda into a medium bowl. Add sugar and salt, then whisk to blend evenly.
- Make a well in the center of the dry ingredients, then add oil, beaten egg, sour cream, milk and vanilla extract and slowly whisk it in until combined and the batter is smooth.
- Spread batter evenly into prepared pan using a small offset spatula and bake for 20-25 minutes until a skewer inserted into the center comes out clean. Transfer to a wire rack and let cool completely in the pan. Trim the top of the cake to level it out and make it flat if necessary, but I never need to because it always bakes up nice and flat.
- Make the mousse. Place finely chopped dark chocolate and milk chocolate in a medium heatproof bowl and set aside.
- Place the milk in a heatproof measuring jug and microwave for 45-60 seconds until steaming. You can also heat it in a saucepan but be sure to cover the pot so you don’t loose too much water through evaporation.
- Combine egg yolks and sugar in a 1 quart stainless steel saucepan (this is my go-to pouring saucepan that everyone asks me about) and whisk until smooth and evenly blended. Very slowly pour in the warm milk while whisking until it is all combined. Transfer the pot to the stove and stir constantly using a rubber spatula or wooden spoon over medium-low heat for 5-7 minutes until it thickens. It should coat the back of a spoon like thick cream. Immediately pour the hot custard over the chocolate, add salt and stir until smooth and the chocolate is completely melted. If necessary, (like if it is cold in your house) place the bowl in the microwave and heat on low power for just 20-30 seconds to melt any residual pieces of chocolate. Let cool for about 10-15 minutes so it is no longer hot.
- Place cold cream in a medium bowl and use an electric hand mixer to whip to medium peaks which is somewhere between soft and stiff peaks. When you lift the beaters, the cream chocolate curl just slightly when it reaches this stage. Take one third of the whipped cream and fold it evenly into the chocolate custard to lighten it up. You don’t need to be too gentle at this first stage. Gently fold in the remaining cream in 2 stages being careful not to deflate the air. Watch the video tutorial to see the folding technique I use.
- Spoon the mousse over the cooled cake still in the pan and spread it out evenly using a small offset spatula. Place it in the fridge for at least 4 hours to set.
- When you're ready to serve, use a small offset spatula to release the sides of the cake/mousse from the pan where you have no parchment, then use the parchment overhang to lift it out of the pan. Sift cocoa powder over the top before slicing and serving.
