Preheat the oven to 175 °C/ 350 °F.

Crack the eggs into a bowl.

Using an electric mixer or a hand whisk, beat until frothy.

Add the salt and slowly sift in the Erythritol while beating.

Gently fold in the almond flour and add the vanilla.

Pour the dough into a tray (38 x 28 cm/ 15 x 11 inches) lined with heavy-duty parchment paper.

Bake for 8-10 minutes, until set and lightly golden.

Do not overcook the sponge or it will break when you roll it.

When done, remove the tray from the oven.

Flip the sponge onto another piece of parchment paper and cover with a dump (but not too wet) kitchen towel.

Leave to cool down for 2-3 minutes.

Then, gently peel the parchment off the sponge.

While still warm, tightly roll the sponge with the parchment paper.

Let it cool down for a few minutes while you prepare the filling.

Note: it may help if you score a small shallow indention with a sharp knife, about 1 cm (1/2 inch) along the edge on the side you will roll.

Prepare the filling by mixing the homemade Nutella and mascarpone cheese in a bowl.

Once the sponge has cooled down, gently unroll it.

Spread the Nutella-mascarpone filling inside.

Do not go too close on the edges to prevent the filling form oozing out as you roll it.

Roll the cake by pulling the paper towards you and use your other hand to shape the sponge into a roll.

Place in the fridge while you prepare the ganache.

To make the ganache, break the chocolate into small pieces and place in a small bowl.

Heat the butter with the cream in a saucepan over medium-high heat.

Once foam starts to develop on top, slowly pour it over the chocolate while stirring, allowing the chocolate and the cream mixture to combine.

Set aside to cool.

What if my ganache breaks? If the fat separates from the rest of the ingredientsdont panic.

Slice and enjoy! Keep refrigerated for up to 5 days.