Step by step
Add the egg yolks, salt, vanilla extract and 50 g sugar to the bowl of a stand mixer fitted with the Wire Whisk. Mix on speed 10 until pale.
In a different bowl, whisk the eggwhites until frothy then add the vinegar and slowly sprinkle in the remaining caster sugar.
Very gently fold the egg whites into the yolks until just combined.
In a small bowl, mix the flour, baking powder, milk and oil. Pour into the egg mixtures and gently fold until incorporated.
Pour the batter into a lined baking tray of approximately 33 cm x 22 cm. Smooth the batter with the back of a spoon. Bake for 30 minutes at 170°C
Take the baked cake immediately out of the baking tray and peel off the baking paper. If necessary, cut the edges of the cake so you obtain perfectly straight lines. Spread the jam over the cake and roll up tightly. Store in the fridge until you are ready to serve.
Decorate to your own taste with buttercream, fresh flowers and fresh fruit.