Note: Continental Butter Cream is for using inside the cake (with a layer of jam on top).
Note: This recipe has measurements for 5 different amounts of butter cream.
For a 13 x 9" or 10" square cake use ½ recipe
Spread on to each layer, with a slightly thicker edge around the sides so it will contain the jam or lemon curd, or whatever you add on top.
Making the soft ball syrup is by far the trickiest part so here's more detail on doing that.
In a saucepan mix the sugar and water until the sugar dissolves. Then turn the hob on to medium heat. DO NOT stir the mixture. Use a brush to brush the sides of the pan with cold water.
As the mixture is simmering the sound will change. It will start to sound sticky. Use the end of a metal spoon and dip it in the mixture. You should be able to push the blob on the end of the spoon and shape it with your fingernail. That's soft ball.
Immediately turn the hob off, turn the mixer back on high and slowly drizzle the sugar syrup into the egg and sugar mixture. Once it's all in there keep the mixer going until the sides on the mixer bowl are cool.