Preheat your oven to 400℉ (200℃). Line a jellyroll pan with parchment paper, greased with baking spray.

In a medium bowl, sift together the plain flour and espresso powder until evenly mixed.

Beat the egg whites in a clean bowl until foamy. Gradually add sugar, beating until medium peaks form, about 2-3 minutes.

In a separate bowl, beat together the whole eggs, egg yolks, and sugar until pale and thick, about 5-10 minutes.

Gently fold the meringue into the egg mixture, then slowly incorporate the flour and espresso mixture.

Pour the batter into the prepared jellyroll pan, spreading evenly. Bake for 8-10 minutes until set and lightly golden.

Dust cocoa powder over the baked cake while warm, then invert the cake onto parchment and roll it up from one end.

Let the rolled cake cool completely at room temperature before unrolling it.

In a mixing bowl, beat the cream, powdered sugar, vanilla extract, and coffee liqueur until soft peaks form, then gently fold in mascarpone cheese.

Spread half the filling over the unrolled cake, roll tightly back into a log shape, and frost the outer layer with remaining filling.

Dust the outer layer with cocoa powder before serving, slice, and enjoy!