Preheat the oven 200°C (392 ℉).
Beat eggs and sugar for a fluffy texture, the base for a light Swiss roll.
Add vanilla extract to elevate the batter's flavor.
Combine flour and baking powder in a separate bowl. Gradually mix into egg-sugar blend for structure.
Gently blend in flour mixture using a spatula, keeping the fluffiness. Also, add milk for moisture.
Place non-stick baking paper on a 30 x 40 cm sheet. Spread batter evenly with the spatula.
Bake for 5 minutes for the desired Swiss roll texture.
Sprinkle sugar on another baking paper. Flip the cake onto it and peel off the original paper.
Brush the paper's back with cold water to prevent sticking.
Spread blueberry marmalade evenly over the cake.
Roll the cake using the baking paper for the iconic shape. Keep it wrapped in baking paper to maintain shape while cooling.
Slice and enjoy. Wrap any leftovers in the same baking paper for freshness.