It is a well-known fact that during holidays, everything is more lavish and ostentatious; and this cake, with its five layers of biscuits, chocolate, cream, and liqueur, is the perfect symbol of the season. Modest enough to be an everyday cake, yet sumptuous enough to be the centrepiece of any party or celebration.
Chocolate and hazelnuts pair immensely well, especially with the nuanced noisette flavours highlighted by the Frangelico, and the vanilla custard base balances and lightens the flavours nicely. If you are anything like me, and you love ice cream cakes, slyly place it in the freezer about 15 minutes before serving, and it will have a marvellous, ever so slightly frozen, texture.
Ingredients
For the base
200 grams vanilla biscuit crumbs
75 ml double cream
75 grams unsalted butter, melted
1 teaspoon vanilla bean paste
For the Ganache layer
100 grams dark chocolate
60 ml double cream
For the filling
600 ml whole milk
60 grams cornflour
100 grams granulated sugar
2 large egg yolks
1 teaspoon vanilla bean paste
100 grams dark chocolate
150 grams unsalted butter, room temperature, divided
100 grams ground roasted hazelnuts
100 ml Frangelico, divided
For the ganache glaze
50 grams dark chocolate
50 ml double cream
For the decoration
200 ml double cream
3 tablespoons unsweetened cocoa powder
1 teaspoon vanilla bean paste
50 grams ground roasted hazelnuts
Preparation
Because the custard base will require some time to cool down, start by taking away about 150 ml of milk, and whisking it really well with sifted cornflour, egg yolks, vanilla, and the sugar in a medium bowl, and set it aside. Pour the rest of the milk into a heavy-bottomed saucepan, and place it over medium high heat, so the milk can come up to a boil slowly. Once it starts boiling, add in the cornflour mixture in a thin stream, and cook, while whisking constantly, until it thickens up, and becomes a very rich custard, about 2-3 minutes. Remove it from the heat and strain it through a mesh strainer, just in case there are some pieces that have not cooked properly or have not dissolved. Divide the cooked base into two parts, and add finely chopped dark chocolate to one part. Mix well until the chocolate melts into the custard, then cover both parts with cling film, and let them cool down to room temperature.
For the biscuit base, place the biscuit crumbs into a large bowl, pour in the melted butter, double cream, and the vanilla bean paste, and start mixing with a wire whisk or with a fork, until the crumbs are moistened. Once the base is prepared, place the cake ring (15 cm) on the serving platter, line it with a tall strip of acetate, and press in the biscuit base. It may be slightly crumbly, but be patient with it, and press it down evenly and firmly, then set aside.
To make the ganache, chop up the chocolate and bring the double cream almost to a boil, then pour it over the chocolate and set it aside for a minute or two. Once the chocolate has started to melt, mix vigorously with a small spatula until everything is melted. Pour the Ganache over the biscuit base, and tap the cake gently on the counter a few times, so that any possible air bubbles come up to the surface. Place the cake into the refrigerator while you work on the fillings.
Once the custards are at room temperature, and ready, place the softened butter into a large bowl, and beat with an electric mixer on high, until it becomes very light and creamy, and resembles buttercream, about 3-4 minutes. Divide the whipped butter in half, and add each half into the cooled custards. Blend this well, at least 2-3 minutes per filling, so they have a light and airy texture. Add the ground hazelnuts and half of the Frangelico to each of the fillings, and blend them well separately.
Take the cake base out of the refrigerator, and very gently spread the vanilla filling over the ganache. I strongly suggest not pressing the filling down into the ganache, so it retains its mousse-like texture. Place the platter into the freezer for about 10 minutes, then spread the chocolate layer in the same fashion. The edges might seem a tad untidy, but it is well worth the sacrifice for the mousse texture. Place the cake into the refrigerator for at least 4 hours, preferably overnight, so it can fully firm up.
Once the cake is ready, chop up the dark chocolate and heat up the double cream almost to a boiling point, then set it aside for about 10 minutes, until it is chilled, but still pourable. Whip up the double cream with the vanilla and the cocoa powder until soft peaks form, and set it aside. Take the cake out of the refrigerator, carefully remove the cake ring and the acetate, then drizzle the cooled ganache all over the edges of the cake, letting it drip down the sides. Place the whipped cream into a piping bag fitted with a large nozzle (1M), and pipe a decorative border on the top edge of the cake, and finish everything off by sprinkling ground hazelnuts all over the top of the cake. If you have any unused ganache, drizzle it messily over the hazelnuts and the cream. Place the cake back into the refrigerator until serving time. Yields 16-20 servings.