Preheat the oven to 200C
Beat together the caster sugar and Unsalted Whirl until the sugar has dissolved and the mix as turned pale
Add 1 egg and a table spoon of sieved flour
Mix gently until just combined
Repeat with the second egg
Add the rest of the flour, vanilla extract and water
Mix until just combined
Divide into bun cases or place into a greased and lined 18cm cake tin
Bake in the oven until the top is golden brown. Check that the cake is cooked all the way through by inserting a metal skewer (if it comes out clean it is ready)
To assemble the cake, place one cake upside down onto a plate and spread it with plenty of jam. If you want to, you can spread over Whirl Sweetened Whipping cream alternative too. Top with the second cake, top-side up. Sprinkle over the caster sugar.