Description
An impressive three-layer chocolate dessert featuring moist dark chocolate cake layered with homemade dark and white chocolate mousses and topped with rich chocolate ganache. Perfect for special occasions and entertaining.
Ingredients
Dark & White Chocolate Mousse Filling:
- ½ cup (4 oz) dark chocolate chips (get the good stuff, trust me)
- ⅓ cup warm water
- ¼ cup dark cocoa powder (Hershey’s Special Dark is fine)
- ¾ cup white chocolate chips (don’t cheap out here either)
- ⅓ cup heavy cream
- 2⅓ cups cold heavy whipping cream (keep it cold!)
- ¼ cup powdered sugar
- 2 teaspoons vanilla extract
- ½ teaspoon fine salt (seriously, don’t skip this)
Chocolate Ganache Frosting:
- ¾ cup heavy whipping cream
- 1 cup + 1 tablespoon dark chocolate chips
- 2 tablespoons unsalted butter, room temperature
- 1 tablespoon light corn syrup (makes it super shiny)
- ¼ teaspoon fine salt
Dark Chocolate Cake Layers:
- 2½ cups granulated sugar
- 2¼ cups all-purpose flour
- ¾ cup dark cocoa powder
- 2½ teaspoons baking powder
- 1 teaspoon fine salt
- 1 cup unsalted butter, room temperature
- 1 cup egg whites (the carton kind works great)
- 1½ cups buttermilk (this is the magic ingredient)
- 2 tablespoons vegetable oil
- 2 teaspoons vanilla extract
- 1 teaspoon instant coffee (whatever you have is fine)
Chocolate Simple Syrup:
- ½ cup water
- ½ cup granulated sugar
- 1 tablespoon unsweetened cocoa powder
Instructions
Toss your mixing bowl and beaters in the freezer right now. Cold everything is what makes cream actually whip instead of just getting tired.
Pro Tip: Learned this when my stand mixer broke on Easter Sunday and I had to use a hand mixer. Cold bowls saved my arms from falling off.
Melt your chocolate chips slow and easy – microwave in 20-30 second chunks or use a double boiler if you’re fancy. Don’t rush or you’ll get chocolate cement. In another bowl, whisk that warm water and cocoa until it’s smooth, then mix into melted chocolate. Let it cool down.
White chocolate is a drama queen and burns if you breathe on it wrong. Melt it with the cream super slowly, stirring the whole time. Should end up smooth and creamy. If it gets grainy, you moved too fast.
Get that cold bowl and whip 2 cups cream with powdered sugar, vanilla, and salt until you see soft peaks. Takes maybe 3 minutes with a good mixer. Stop at soft peaks or you’re making butter.
Split the whipped cream between two bowls. Fold the cooled dark chocolate into one, white chocolate into the other. Fold means gentle scooping with a rubber spatula, not beating the life out of it. Cover and stick in fridge for 2 hours minimum.
Pro Tip: My grandma used to say fold like you’re putting a baby to sleep. Took me years to understand what she meant, but gentle is everything here.
Heat that cream until it bubbles around the edges. Pour over chocolate chips and count to sixty – set a timer because I always cheat. Stir from center out until glossy. Add butter, corn syrup, salt. Cover with plastic wrap right on the surface so it doesn’t get a weird skin.
Oven to 350°F, grease your pans good. Mix dry stuff first, then work in room temp butter until it looks like wet sand. Gently stir in egg whites, then buttermilk in two parts. Add oil, vanilla, coffee last.
Pour into pans, bake 40-45 minutes for big pan, 34-37 for rounds. Done when toothpick has some moist crumbs, not totally clean. Don’t overbake or it gets dry.
Pro Tip: Cool for 10 minutes then freeze for 30. Learned this after destroying two cakes trying to level them warm. Cold cake actually cooperates with knives.
Boil water and sugar, take off heat, whisk in cocoa. Keeps cake moist and adds more chocolate flavor. Don’t skip this step.
Dab ganache on plate to stick first layer. Brush with syrup, spread dark mousse, then white mousse. Second layer, more syrup, press gently. Chill 15 minutes, then ganache on top.
Notes
Good chocolate costs more but cheap stuff tastes like wax crayons. Keep bowls in freezer all the time because cold cream whips better. When folding mousse, stop the second it looks combined – don’t keep stirring just because.
Ganache too thick? Ten seconds in microwave. Too thin? Fifteen minutes in fridge. Should spread like frosting, not pour like syrup. Cold ingredients make assembly easier so don’t rush the chilling steps.
- Prep Time: 30 minutes
- Cook Time: 45 minutes + 2 hours 30 minutes (chilling/assembly)
- Category: Dessert
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 slice
- Calories: 466
- Sugar: 38g
- Sodium: 285mg
- Fat: 28g
- Saturated Fat: 17g
- Unsaturated Fat: 9g
- Trans Fat: 0g
- Carbohydrates: 52g
- Fiber: 4g
- Protein: 6g
- Cholesterol: 65mg