Preheat the oven to 350°F (175°C) and line a jelly roll pan with parchment paper.
Prepare the chocolate sponge cake batter by combining the dry and wet ingredients, then spread evenly into the prepared pan.
Bake for 10–12 minutes until the cake springs back when lightly touched.
Turn the warm cake onto a clean kitchen towel dusted with powdered sugar and gently roll it up. Allow it to cool completely.
Unroll the cake and spread an even layer of mocha whipped cream filling.
Carefully roll the cake back into a tight log and refrigerate for at least 1 hour.
Dust with cocoa powder or powdered sugar, slice, and serve chilled.