1. Preheat the oven to 210 ° C.
2. Separate the white from the egg yolks and mix the yolks with the sugar until the mixture turns white. Add the melted butter and mix.
3. Whip the egg whites until stiff.
4. Gently fold in half the egg whites, then half the sifted flour and so on.
5. Pour onto a baking sheet with a baking sheet forming a large rectangle and bake for 10 min.
6. Right out of the oven, place the biscuit on a damp cloth. Roll it up, leave it for a moment then unroll it.
7. Spread the jam on the cookie then roll it up. Sprinkle with icing sugar for decoration.