Ingredients
- 1/2 cup unsalted butter, plus extra for greasing
- 3/4 cup plus 2 tablespoons granulated sugar
- 8 ounces bittersweet chocolate, finely chopped
- 1/2 cup Nutella or hazelnut spread
- 6 large eggs
- 1/2 cup hazelnut flour or almond flour
- 2 tablespoons unsweetened cocoa powder
- 1 teaspoon kosher salt
- 1 cup heavy cream
- 1/4 cup confectioners’ sugar
- Pinch of kosher salt
- 1 cup sour cream
- 1/4 cup Nutella
- Maraschino cherries for serving (optional)
Instructions
- Preheat the oven to 350°F (175°C) and grease a 9-inch springform pan. Sprinkle a little sugar inside the pan to coat.
- In a heatproof bowl, combine the chopped chocolate, Nutella, and butter.
- Place the bowl over simmering water and stir until smooth and melted. Let cool slightly.
- Separate 4 eggs, placing the whites in one bowl and the yolks in another.
- Add the remaining 2 whole eggs to the yolks along with the hazelnut flour, cocoa powder, and salt. Whisk until smooth.
- Fold the egg yolk mixture into the melted chocolate mixture.
- Using an electric mixer, beat the egg whites while slowly adding 3/4 cup sugar until stiff glossy peaks form.
- Fold the whipped egg whites gently into the chocolate batter in batches until fully combined.
- Pour the batter into the prepared pan and smooth the top.
- Sprinkle the remaining 2 tablespoons sugar over the surface.
- Bake for 35 to 40 minutes until puffed, cracked, and slightly jiggly in the center.
- Allow the cake to cool completely.
- For the topping, whip the heavy cream, confectioners’ sugar, and salt until medium-stiff peaks form.
- Fold in the sour cream, then gently swirl in the Nutella.
- Serve the cake with the topping spooned over slices and garnish with cherries if desired.
Notes
- The cake naturally sinks in the center as it cools, creating its signature texture.
- Almond flour can replace hazelnut flour.
- Espresso powder intensifies the chocolate flavor.
- Dark chocolate with 70% cacao creates a richer taste.
- Toasted hazelnuts add extra crunch and flavor.
- Fresh berries pair beautifully with the rich chocolate.
- Store the cake at room temperature for up to 2 days or refrigerated for up to 5 days.
- Freeze individual slices for up to 2 months.
- Allow refrigerated cake to sit at room temperature before serving for the best texture.
- Prep Time: 25 minutes
- Cook Time: 40 minutes
- Category: Dessert
- Method: Baking
- Cuisine: European
- Diet: Gluten Free
Nutrition
- Serving Size: 1 slice
- Calories: 520
- Sugar: 32g
- Sodium: 240mg
- Fat: 39g
- Saturated Fat: 21g
- Unsaturated Fat: 15g
- Trans Fat: 0g
- Carbohydrates: 38g
- Fiber: 3g
- Protein: 8g
- Cholesterol: 170mg
