Cover a shallow rectangular tin with parchment paper of about 22 x 33 cm. Warm up the oven at 200 C

Place a large bowl or pan over hot water and whisk the eggs and sugar with an electric mixer. Make sure the water never boils

It will start forming a thick mixture.

Whisk vigorously until you can form a ribbon trail on the surface.

Remove from the heat and whisk until it cools down, for about 5 minutes

Gently stir in the flour making sure the mixture does not deflate

Pour the mixture onto the slightly buttered parchment paper and cook in the oven for about 20 minutes, checking without opening the oven that the top is nicely browned

Once cooked, let it rest for 10 minutes then move to a rack to cool down completely. In the meantime you can prepare the cream for the filling.

In a pan, pour and combine all the ingredients for the cream except the butter.

Cook in bain-marie until the cream reach the consistency of a custard cream.

Take away from the heat and add the butter. Mix until the butter is all melted and the cream has taken a yellowish colour.

Prepare all the ingredients you want to use for composing and decorating the roll. Here I have grated pistachios and homemade crystallized violets

Turn the sponge upside down and spread the cream over the sponge

With the help of the parchment paper start rolling the sponge over

Move the roll into the serving dish

Cover with the rest of the cream and sprinkle with the grated pistachios

Decorate with the crystallize violets and clean the side of the dish

The cake is now ready to be served. If the ambient temperature is too hot you can store it in the fridge and take it out 30 minutes before serving. Enjoy!