I give you the exact recipe that I took sure the mercotte site, BUT, I also give you my impressions .... I took a mold flexipan biscuit roll, the big, because 20/30 it seemed to me really small compared to the amount of Russian background ......
whipped cream (40cl liquid cream + 250gr mascarpone) and sugar according to taste. When the whipped cream is firm, divide it in 2. In a half add 100g White chocolate melted in the bath and quickly beat. in the other half ......