Preheat the oven to 350°F (175°C) and line a jelly roll pan with parchment paper.
Prepare the sponge cake batter and bake for 10–12 minutes, until lightly golden and springy.
Turn the warm cake onto a clean kitchen towel dusted with powdered sugar and gently roll it up. Allow it to cool completely.
Brush the cooled sponge with espresso or coffee syrup for extra flavor.
Spread an even layer of mascarpone whipped cream filling over the cake.
Roll the cake tightly, dust with cocoa powder, and chill in the refrigerator for at least 1 hour.
Slice and serve chilled, garnished with chocolate shavings or coffee beans if desired.