This Ferrero Rocher cake is the ultimate celebration cake with moist chocolate hazelnut sponges, silky Nutella mousseline cream (cooked chocolate pastry cream enriched with Nutella and butter) that is very well balanced in sweetness, lots of crunchy hazelnuts, and crushed Ferrero Rocher chocolates.
In a large enough bowl with the help of a Hand whisk, mix together sugar and egg yolk until slightly fluffy for about 1-2 minutes
Mix in corn starch and flour, and vanilla until throughly incorporated and have a smooth paste
Bring milk to boil in a saucepan on medium heat then remove it as soon as it starts simmering
Pour the warm milk over the egg yolk mixture slowly while whisking vigorously with a Hand whisk.
Pour the mixture back into the saucepan and cook on medium heat for a few minutes until it thickens. Concretely it is approximately 1 min after the first boil. It might get lumpy first, don't worry just keep whisking and the cream will get smooth and glossy. If in doubt, strain the pastry cream for a lump free, creamy end result
Add in chocolate in 3 stages, and mix with a Rubber spatula until completely incorporated. Place the cream into a shallow bowl and cover the entire surface with plastic wrap to avoid skin forming on top. Let it cool
Pour wet ingredients into dry ingredients then fold just until combined
Divide batter equally into 3 cake pans with the help of a Digital scale
Bake for 25-30 min or until skewer inserted in the middle of the cakes comes out clean
Cool the chocolate sponges on Cooling rack. Chill them in the fridge before assembling the cake
Preparing the Nutella mousseline cream
The Nutella mousseline cream can be made with room temperature pastry cream, Nutella, cocoa powder, and room temp soft butter. Make sure everything is room temp otherwise the mixture might curdle
Once pastry cream is set and at room temp, prepare the mousseline cream by whipping room temp butter first for a few minutes, then whip in the cocoa powder and Nutella for 1-2 minutes
Start adding in the room temperature pastry cream in 4 stages until cream reaches a stable yet fluffy texture. Do not over whip the mixture as it can become runny
Chill the cream if needed for an hour, otherwise proceed with assembling the cake
Assembling
You will need to use the cream for: 1. filling 2. frosting 3. piping decoration so make sure you have enough cream left for each
Start layering the cake from bottom to top and fill each layer with the Nutella frosting. Pipe cream on top, another layer around the sponge then fill the middle with crushed Ferrero Rocher chocolate
Continue with the second layer and apply the same. Finally, finish with a 3rd layer of chocolate sponge cake
At each layer please check how even the layers are, and make sure they are symmetrical with even layers. Chill the cake either 1h in the fridge or 15min in the freezer before proceeding with frosting on the outside
Once the cake is nicely chilled, frost the cake. You can pipe the cream around the cake first, then smooth it with an offset spatula. Try to work as neat as possible, but no need to worry if it is not perfect.
Chill the cake again either 1h in the fridge or 15min in the freezer before proceeding with decoration
Apply roasted chopped hazelnut all around and on the top of the cake and pipe some decoration on top using the same Nutella mousseline cream
Video
Notes
INGREDIENT NOTES:
Measure your ingredients with a Digital scale for accuracy
All ingredients for the chocolate cake must be at room temperature to properly emulsify: eggs, milk, coffee etc.
Do not skip salt that will balance the sweetness of this cake
You can either purchase the hazelnut flour or use roasted hazelnut and blend it together with the flour. Make sure that you blend it with the flour together otherwise the hazelnut would become too oily on its own
For the Nutella mousseline cream, it is key to use good quality unsweetened dark cocoa powder and semi-sweet chocolate so that they don´t overpower the Nutella taste, but balancing it
TECHNIQUE NOTES:
Make sure you read my Expert tips section above to maximize your success. A short recipe alone is not able to cover all the necessary details, and science behind baking. Consider this recipe more like an in-depth tutorial, literally the only recipe you will ever need to make delicious Ferrero Rocher cake
Chill the chocolate sponges before making any layered cake
Assemble the cake on the serving tray you are planning to serve as at later stage you won´t be able to move the cake
Let the pastry cream be properly set before whipping it up into mousseline cream. While whipping, pay very close attention to the consistency and stop whipping immediately after it gets fluffy. Overbeating would result in breaking the cream and instead of becoming stiffer, in fact, it will get runnier
Make sure you chill the cake in between applying the different layers and frostings just as stated in the recipe. That is a standard procedure for making any layered cake, and skipping it would result in best in class baking disasters
If you have never used a piping bag and piping nozzle before, it is worth making a cheaper buttercream and practice before