Preparation

To make the Nutella swirls, first prepare the roulade dough: break the room-temperature eggs into a bowl, flavor with the vanilla extract, pour in the sugar, and beat at medium speed using a hand mixer ; it will take a few minutes for it to become light and frothy.

Fold in the sifted flour, stirring gently from top to bottom with a spatul.

Now divide the mixture in half and pour into two separate bowls.

Add the cocoa powder to one of the bowls, sifting it and mixing gently from top to bottom so that the mixture does not separate .

Grease a 12x15-inch (30x38-cm) sheet pan and then arrange parchment paper on the base and sides, ensuring it is well stuck down.

Pour in the light-colored mixture , level the surface with a spatula, and bake in a preheated conventional oven at 350°F (180° C) (placing the sheet on the on the top rack) for 10-12 minutes.

Once cooked, take the roulade dough out of the oven and immediately pour the dark-colored mixture over it .

Spread the mixture evenly with a spatula and then bake for a further 10 minutes in a conventional oven at 350°F (180°F), again on the top rack.

Once cooked, take the roulade dough out of the oven and cover the surface with a sheet of parchment paper.

Then cover this with a dish towel to keep it from drying out .

Leave the roulade dough base to cool.

Once it has reached room temperature, gently remove the parchment paper , carefully turn the roulade dough over and remove the parchment paper from the light-colored side, still working very gently .

Even off the edges with a knife, then place the base back on a sheet of parchment paper, add the Nutella and spread it out with a spatula, stopping ½ in (1 cm) from the ends of the long sides, then start to roll up the base with the aid of the parchment paper .

Once you’ve made a roll, wrap it in parchment paper, carefully sealing the ends, and leave to set in the fridge for an hour.

Once this time is up, take out the roll, which should now be very firm , and slice it into 12 swirls.

Now add the topping: chop up the dark chocolate and melt in a bain-marie or microwave.

Dip the swirls in the melted chocolate on one side only and leave them to dry on a rack.

Once the chocolate has set, your Nutella swirls are ready to be enjoyed!.