Separate the egg yolks and whites. Beat the egg whites with the salt until stiff, then add the sugar and vanilla, and mix for a few more minutes.

Add the yolks one by one, mixing to combine.

Mix the cocoa with the flour, sift, and gradually fold into the mixture using a wooden spoon or spatula.

Line a 10x14 inch baking pan with parchment paper and pour the batter on top, spreading it evenly.

Bake in the oven at 320°F (160°C) for about 12 minutes.

Remove and let cool.

In a bowl, beat the whipped cream with the vanilla until fluffy, add the sweetened condensed milk, mix, and refrigerate until the cake cools.

Reserve a little cream for spreading on top, and spread the rest over the cake. Wash and hull the strawberries, slice them, and place on top of the cream.

Carefully and gently roll the cake into a log and place on a platter or tray. Spread the remaining cream over the roll, place sliced strawberries all over, and sprinkle with grated chocolate. You can decorate it to your taste, even adding chocolate glaze on top if you like.