• For Cake Layers:
  1 3/4 cup (300g) bittersweet chocolate chips
  1/2 cup (150g) Nutella or other hazelnut-chocolate spread
  1 cup (150g) hazelnuts
  1/4 cup (31g) confectioner's sugar
  1/4 cup (30g) unsweetened cocoa powder
  1/4 cup (31g) all-purpose flour
  2 teaspoons (8g) baking powder
  1/8 teaspoon salt
  1 cup (226g) butter, softened at room temperature
  1/2 cup (100g) white granulated sugar
  7 eggs, separated
• 
  For Nutella Frosting:
  2 cups (450g) butter; softened at room temperature
  1 cup (300g) Nutella
  1/4 teaspoon salt (optional)
  2 cups (250g) confectioner's sugar
   
• Other ingredients:
  crunchy wafer or waffle cookies, crushed
  Ferrero Rocher candies and hazelnuts for garnish

• 1. Preheat oven to 350F and line 2, 8-inch cake pans with parchment paper and spray down sides with non-stick spray.
  2. Melt chocolate chips in a microwave or double boiler. While chocolate is still hot, add Nutella and whisk until smooth.
  3. Place hazelnuts, flour, cocoa powder, baking powder, salt and confectioner’s sugar into food processor and pulse until fine flour forms. Set flour aside.
  4. Next, place sugar and butter into a mixer bowl and whisk on high speed until light and fluffy. Add egg yolks; mix until well combined. Fold in the chocolate and Nutella mixture, followed by hazelnut flour.
  5. Transfer chocolate batter into a separate bowl and clean mixer bowl very well. Place egg whites into a clean mixer bowl and whisk until stiff peaks form. Gently fold in the prepared cake batter into egg whites, being careful not to flatten the egg whites. Fold gently until uniform batter forms.
  6. Pour batter into prepared cake pans and bake in preheated oven, until toothpick inserted into the center comes out clean, about 35-40 minutes. Remove cakes from pans and let cool completely on wire racks. Cake layers will be fragile; handle carefully. Once completely cooled, split the layers in half, forming 4 layers total.
  7. For frosting, place softened butter and Nutella into a mixer and whisk until light and fluffy. Gradually add the confectioner's sugar until frosting is thick and fluffy. Can add a pinch of salt for flavor.
  8. To assemble cake, top with frosting and crushed cookies between each layer. Frost sides and top; garnish top with candy, hazelnuts and/or cookies.
  9. Keep Ferrero Rocher cake refrigerated. When getting ready to serve, remove cake about 1 hour before serving to allow buttercream to soften.