From the macaron cookie top to the Nutella ice cream filling, this cake is a celebration of all things chocolate-hazelnut.
COOKIE BASE & TOP
1 1/4 cups (140g) hazelnut meal
3/4 cup (84g) almond meal
1/2 cup (100g) granulated sugar
5 egg whites
1 1/2 cups whipping cream
1/4 cup Nutella
1 tsp vanilla extract
1 cup Nutella, gently warmed in the microwave
1 Ferrero Rocher
(adapted from La Boulange: Cafe Cooking at Home)
Preheat the oven to 375F. Line a baking sheet with parchment paper (if your parchment refuses to lay flat, a little oil on the edges will help it adhere) and use a pencil and the bottom of the springform pan to trace two 6″ circles, leaving about 2″ in between to leave room for expansion.
In a small bowl, combine the hazelnut meal, almond meal, and 1/3 cup (67g) of the sugar.
Place the egg whites in the bowl of a stand mixer fitted with the whisk attachment. Beat the whites on medium-high speed (8 on a KitchenAid) until soft peaks begin to form.
Add about a third of the remaining sugar, then continue beating, adding the rest of the sugar a little at a time, until stiff peaks form.
Using a silicone spatula, slowly fold the dry ingredients into the whipped whites until combined.
Transfer the mixture to a piping bag, fitted with a ~1/4in round tip if you have one. Starting from the center of each of your traced circles, pipe the batter into a spiral. This will take some effort–hang in there! Aim to nearly but not entirely fill each 6″ circle, or they may expand too much to fit in the pan. (As you can see from the photo, I got overzealous and had to get creative with decorations to accommodate.)
Bake for 20-25 minutes, or until golden-brown.
Transfer to a cooling rack. (While the cookies cool, you can move on to make the ice cream filling.)
Once the cookies are room temperature, choose the less attractive of the two; that will be your base. Fit the base inside the springform (directly on the bottom of the pan), trimming the edges if necessary. Reserve the other cookie for the top of the cake.
Wrap the bottom of your springform pan in tinfoil to ward against leakage.
Clean out the bowl of the stand mixer. Using the paddle attachment, add the ice cream and mix on low speed to soften. If using hazelnut ice cream, proceed to the next step; if using vanilla, add the Nutella and mix just until uniform.
Transfer the mixture to your springform pan. Cover with plastic wrap and freeze for at least an hour, or until solid.
Remove the pan from the freezer and gently release the springform, using a knife to loosen the edges if necessary. Transfer the unmolded cake to a rotating cake stand, if you have one.
Using a cake spatula or the flat side of a knife, smooth the edges of the cake.
Working quickly, spread warmed Nutella over the surface of the cake and top with the other cookie.
For the decorations shown, sift a little powdered sugar over the top. Using a piping bag fitted with a star-shaped tip, pipe Nutella around the edges of the top and the base. Cut a Ferrero Rocher in half and place in the center of the cookie top. Eat the other half.
Serve immediately for creamier Nutella, or return to the freezer for a chocolate shell-like consistency.
Cut with a serrated knife and some arm work.