Chocolate Hazelnut Layered Cake
A rich, elegant layered cake with soft vanilla sponge, chocolate cake, creamy chocolate mousse, and a glossy chocolate ganache topping.
Ingredients
For the Vanilla Sponge Layer
• 2 cups flour (250g)
• ¾ cup sugar (150g)
• ½ cup butter (115g), softened
• 3 eggs
• ½ cup milk (120ml)
• 2 teaspoons baking powder (8g)
• 1 teaspoon vanilla extract
For the Chocolate Sponge Layer
• 1 cup flour (125g)
• ½ cup cocoa powder (50g)
• ¾ cup sugar (150g)
• ½ cup butter (115g)
• 3 eggs
• ½ cup milk (120ml)
• 2 teaspoons baking powder (8g)
• 1 teaspoon vanilla extract
For the Chocolate Mousse
• 1½ cups whipping cream (360ml), cold
• 1 cup melted milk or dark chocolate (200g)
• ¼ cup icing sugar (30g)
• 1 teaspoon vanilla extract
For the Chocolate Ganache
• 1 cup dark chocolate (200g), chopped
• ½ cup whipping cream (120ml)
For Decoration
• 1 cup chopped hazelnuts or peanuts (120g)
• Whole hazelnuts
• ½ cup chocolate chips or chopped chocolate (80g)
Instructions
Prepare a rectangular baking pan by greasing and lining it with baking paper.
For the vanilla sponge, cream the butter and sugar until light and fluffy. Add the eggs one at a time and mix well. Add the vanilla extract.
Mix the flour and baking powder together. Add the dry ingredients alternately with the milk and mix until smooth.
Pour into the prepared pan and bake at 170°C (340°F) until golden and a toothpick comes out clean. Allow to cool completely.
Prepare the chocolate sponge by creaming the butter and sugar. Add the eggs and vanilla.
Mix the flour, cocoa powder and baking powder together. Add the dry ingredients alternately with the milk.
Pour into a prepared rectangular pan and bake at 170°C (340°F) until fully baked. Allow to cool completely.
For the mousse, whip the cold whipping cream and icing sugar until soft peaks form.
Allow the melted chocolate to cool slightly, then gently fold it into the whipped cream. Add the vanilla and mix until smooth and fluffy.
Place the vanilla sponge layer in a rectangular cake mould or loaf pan.
Spread the chocolate sponge or chocolate mousse layer evenly over it. Continue layering until you achieve the beautiful striped effect.
Chill the cake in the refrigerator for at least 4 hours, or until firm.
For the ganache, heat the whipping cream until hot but not boiling. Pour over the chopped chocolate and allow it to sit briefly. Stir until smooth and glossy.
Pour the ganache over the chilled cake and spread evenly.
Decorate with chopped nuts, whole hazelnuts and chocolate pieces.
Return the cake to the refrigerator for about 30 minutes to allow the topping to set.
Slice with a warm sharp knife and serve cold. 
