Preheat oven to 200°C, then grease and line a 3cm deep, approx. 30cm x 20cm tin.
In a large bowl, use an electric mixer to beat the eggs and sugar together until light and fluffy. Add the water and vanilla essence. Sift flour and gently fold into the egg mixture using a large spoon.
Pour mixture into the prepared tin and bake in oven for about 12-15 minutes, or until the centre is slightly spongy.
Place a piece of baking paper onto a flat work surface and sprinkle with caster sugar. Turn the cake tin straight from the oven onto the baking paper and cover with a slightly damp cloth while it cools.
Once cooled, spread the jam evenly over the cake, leaving a 1-inch border. Repeat with the whipped cream and roll up the Swiss Roll away from you. Transfer to a plate and serve