Description
A towering and indulgent 12 layer chocolate cake made with ultra-moist cocoa cake layers soaked in simple syrup and filled with alternating layers of silky chocolate pastry cream and rich fudgy frosting. A true show-stopping dessert for serious chocolate lovers.
Ingredients
- Chocolate Cake: 4 cups (500 g) all-purpose flour
- 4 cups (800 g) granulated sugar
- 2 cups (170 g) unsweetened cocoa powder
- 4 teaspoons baking soda
- 2 teaspoons baking powder
- 2 teaspoons salt
- 5 large eggs, room temperature
- 2 cups (452 g) sour cream or Greek yogurt, room temperature
- 2 2/3 cups (630 ml) water, room temperature
- 2/3 cup (160 ml) neutral oil
- 4 teaspoons vanilla extract
- Simple Syrup: 1/2 cup (100 g) granulated sugar
- 1/2 cup (120 ml) water
- Chocolate Pastry Cream: 2 1/4 cups (540 ml) whole milk
- 3/4 cup (180 ml) heavy whipping cream
- 1/2 cup plus 3 tablespoons (137 g) granulated sugar, divided
- 1/8 teaspoon salt
- 6 large egg yolks
- 1/4 cup (32 g) cornstarch
- 1/4 cup (57 g) unsalted butter, cold and cubed
- 4 ounces (114 g) bittersweet chocolate, chopped
- 1 teaspoon vanilla extract
- Fudgy Frosting: 12 1/2 ounces (354 g) bittersweet or semisweet chocolate, chopped
- 1 1/4 cups (300 ml) heavy whipping cream
- 1 1/4 cups (250 g) granulated sugar
- 1/4 teaspoon salt
- 1/2 cup plus 2 tablespoons (142 g) unsalted butter, softened
- Optional Garnish: chocolate sprinkles, curls, or chips
Instructions
- Preheat oven to 350°F (180°C). Grease and line four 9-inch round cake pans with parchment.
- Sift together flour, sugar, cocoa powder, baking soda, baking powder, and salt. Add eggs, sour cream, water, oil, and vanilla. Mix until smooth.
- Divide batter evenly among pans. Bake about 25 minutes until a toothpick comes out clean. Cool 15 minutes, then transfer to racks to cool completely. Chill for easier slicing.
- Prepare simple syrup by heating sugar and water until dissolved. Cool completely.
- For pastry cream, heat milk, cream, half the sugar, and salt until simmering. Whisk yolks with remaining sugar and cornstarch. Temper with hot milk, return to heat, and cook until thick. Remove from heat and stir in butter, chocolate, and vanilla. Strain, cover surface, and chill.
- For frosting, heat cream, sugar, and salt until simmering. Pour over chopped chocolate and whisk smooth. Add butter and whisk until glossy. Chill until spreadable.
- Level cakes and slice each into three layers, creating 12 layers total.
- Line a cake ring with acetate. Place first layer inside, brush with syrup, and spread just over 1/2 cup pastry cream. Add next layer, brush with syrup, and spread frosting. Continue alternating fillings until 6 layers are stacked. Freeze until firm.
- Repeat with remaining layers to form a second 6-layer stack. Freeze until very firm.
- Remove from molds and stack one cake atop the other. Smooth sides and garnish as desired. Bring to room temperature before serving.
Notes
- Chilling cake layers before slicing ensures clean, even layers.
- The cake can be assembled and frozen ahead of time.
- Use semisweet chocolate for a slightly lighter flavor.
- Add espresso powder to enhance chocolate depth.
- Allow cake to sit at room temperature before serving for best texture.
- Prep Time: 1 hour 30 minutes
- Cook Time: 40 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 slice
- Calories: 780
- Sugar: 65g
- Sodium: 420mg
- Fat: 42g
- Saturated Fat: 24g
- Unsaturated Fat: 15g
- Trans Fat: 0g
- Carbohydrates: 95g
- Fiber: 5g
- Protein: 9g
- Cholesterol: 155mg
