Instructions:
1. Prepare the sponge:
- Preheat oven to 180°C (350°F). Line a 22–24 cm (9-inch) round cake pan with parchment paper.
- Beat egg yolks with sugar until pale and creamy. Stir in vanilla extract and the ground hazelnuts.
- In a separate bowl, beat egg whites with a pinch of salt until stiff peaks form.
- Gently fold the egg whites into the yolk-hazelnut mixture. Add flour carefully and fold until combined.
- Pour into the prepared pan and bake 25–30 minutes until a toothpick comes out clean. Cool completely.
2. Prepare the chocolate-hazelnut filling:
- Melt chocolate gently over a double boiler.
- Beat butter with powdered sugar until fluffy. Gradually mix in melted chocolate and hazelnut liqueur or coffee.
3. Assemble the cake:
- Slice the sponge horizontally into 2 layers (if thick enough).
- Spread a generous layer of chocolate-hazelnut filling between layers and on top.
- Smooth the sides and sprinkle with chopped hazelnuts or chocolate shavings if desired.
4. Chill and serve:
- Refrigerate at least 1–2 hours before slicing to set the filling.
✨ Tips:
- You can lightly toast the hazelnuts for a deeper flavor.
- This cake pairs beautifully with coffee or a glass of milk.
- For extra indulgence, drizzle melted chocolate on top.
If you want, I can also give you a faster, “one-bowl” version that keeps the hazelnut-chocolate flavor but is much easier to make at home.
Do you want me to do that?