In another bowl, whip the heavy cream until soft peaks form, and in a separate bowl, beat the egg whites with a pinch of salt until stiff peaks form. Now, the fun part: in yet another bowl, whisk together the egg yolks and sugar until light and fluffy, then add in the melted chocolate along with the vanilla extract and cocoa powder. Gently fold the whipped cream into the chocolate mixture and then add the beaten egg whites little by little to maintain that airy texture we crave in mousse.
Once your mousse is ready, it’s time to assemble! Line the bottom of your springform pan with parchment paper to ensure the cake comes out easily. Pour half of the mousse into the pan, then sprinkle half of the toasted hazelnuts on top. Layer the remaining mousse and top it off with the rest of the nuts. Chill in the refrigerator for at least four hours or until firm. The waiting is the hardest part, but the anticipation makes every bite even sweeter!
Pro Tips for Best Results
As I was perfecting this recipe, I found that using high-quality chocolate makes a huge difference in flavor. I tested this with both semi-sweet and dark chocolate, but the latter really brought out that deep, rich taste that pairs beautifully with hazelnuts. Also, I learned to be gentle when folding in the whipped cream and egg whites. It’s important to preserve the volume so your mousse stays light and fluffy.
If you want that Nutella flavor embedded in the mousse, I suggest swirling in that tablespoon of Nutella right at the end before chilling. It adds that fantastic hazelnut chocolate goodness we all love from the classic Ferrero Rocher candies! Lastly, don’t rush the chilling process. I’ve tried cutting corners before, and believe me, the mousse just doesn’t set up the same way when it’s not given enough time.
Common Mistakes to Avoid
One common mistake I made early on was not allowing my chocolate to cool before incorporating it into the egg yolks. This resulted in scrambled eggs, which was a big disappointment! Make sure your chocolate is cool to touch, but still liquid for the best texture. Another pitfall is overmixing the whipped cream and egg whites; I’ve been tempted to whip them to perfection, only to find they lose that delightful fluffiness we’re aiming for.
Another thing to watch out for is not properly greasing your springform pan. I’ve had a couple of cakes stick, and it was heartbreaking to see the mousse tear apart when I tried to remove it. Take the time to use parchment paper on the bottom and a bit of butter or cooking spray on the sides to ensure a flawless removal. Finally, if your mousse doesn’t set, it could be due to too much liquid cream remaining after mixing. When you’re folding, just be cautious about deflating those beautiful bubbles!