Ingredients
Sponge Biscuit
- 5 eggs
- 85 grams (3 ounces) sugar
- 30 grams (1.06 ounces) cocoa powder
- 26 grams (0.92 ounces) flour
- 4 grams (0.14 ounces) baking powder
- 200 grams (7.05 ounces) hazelnuts
Filling
- 200 grams (7.05 ounces) butter
- 200 grams (7.05 ounces) chocolate
- 100 grams (3.53 ounces) Nutella
- 120 grams (4.23 ounces) crunchy waffles
Equipment
- Food Processor
Essential for grinding the toasted hazelnuts to the right texture. Make sure not to over-process to avoid turning the nuts into butter.
- Mixing Bowls
Use different sizes to separate wet and dry ingredients. Stainless steel or glass bowls work best for maintaining the temperature.
- Electric Mixer
Hand or stand mixers are perfect for whipping the eggs and sugar to the desired frothy consistency.
- Silicone Spatula
Great for folding in ingredients gently to maintain airiness. Cleans easily and is heat-resistant.
- 18cm (7.10 inch) Baking Pans
Ensure the batter is evenly spread in these pans for uniform layers. Lining them with parchment paper can help prevent sticking.
- Microwave or Double Boiler
Needed for melting chocolate without burning it. The double boiler method gives you more control over the heat.
- Cake Leveler
Essential for slicing the sponge layers evenly and creating a professional-looking cake.
Instructions
Step 1
Step 2
Step 3
Step 4
Step 5
Step 6
Servings
Variations
Faq
- Can I substitute the hazelnuts with other nuts?
Absolutely! You can use almonds or walnuts, but make sure to toast them for added flavor.
- What if I don't have a food processor?
You can place the hazelnuts in a sturdy plastic bag and crush them with a rolling pin, though the texture might be slightly different.
- How can I ensure my sponge cake layers are even?
Use a cake leveler or a serrated knife to slice the layers, and make sure to measure the batter evenly between the pans before baking.
- Can I prepare the cake ahead of time?
Yes, you can bake the sponge cakes and prepare the filling in advance, then store them separately. Assemble the cake on the day you plan to serve it for maximum freshness.
- How do I avoid curdling the butter when adding melted chocolate?
Ensure the chocolate is at room temperature and add it gradually, one spoon at a time, while continuously whipping the butter.
- Can I freeze the leftover cake?
Yes, you can freeze the cake. Wrap it tightly in plastic wrap and aluminum foil before freezing. Thaw in the refrigerator before serving.