Preheat the oven to 350°F (175°C) and line a jelly roll pan with parchment paper.
Prepare the sponge cake batter by whisking the eggs and sugar until light and fluffy, then gently fold in the flour and vanilla.
Spread the batter evenly into the prepared pan and bake for 10–12 minutes, or until the cake springs back when touched.
Turn the warm cake onto a clean kitchen towel dusted with powdered sugar and carefully roll it up. Let it cool completely.
Unroll the cake and spread an even layer of whipped cream or fruit jam.
Roll the cake back into a tight log and refrigerate for at least 1 hour.
Dust with powdered sugar, slice, and serve chilled.