This is a great recipe (originally WW) I made it with orange and chocolate chips instead of banana & maltesers.
Orange & Chocolate Chip Cakes add the rind of an orange and use orange juice instead of the water in making up the cake and then add 50g choc chips. Not sure if the syns change (I know they worked out the same points)
I also made it using a standard fatless sponge mix instead of bought cake mix. Here's the recipe........not sure of the syns though:
3 standard eggs
75 g./ 3 oz. castor sugar
75 g./ 3 oz. self-raising flour, sifted twice or three times
Break eggs, one at a time, into cup. Transfer to mixing bowl. (It is best to do this in case one egg out of three is bad). Whisk until very frothy. Gradually add sugar. Continue to whisk steadily until mixture is very pale in colour, the consistency of whipped cream and at least twice the volume than it was when you started. To test if eggs and sugar have been whisked sufficiently, lift beaters out of bowl (remembering to switch off electricity first or mixture will fly all over the eplace) and allow it to fall from the beater heads back into bowl. The mixture should stay on the surface, like a decoration, for about half a minute; if it sinks immediately, it's under-whipped and you must continue whisking until the correct consistency is reached. It is vitally important to get this absolutely right because a sponge depends almost entirely on air to aerate it, especially if it's made with plain flour.
Sprinkle all the sifted flour all at once over top of the whisked eggs and sugar. Using a large metal spoon or thin plastic spatula, gently and slowly fold in flour by flipping the spoon or spatula over and over. Occasionally cut athe edge across the base of the bowl to lift up and incorporate any flour that may have sunk to the bottom. When smooth and evenly combined, and it is obvious that all the flour has been worked in add banana/maltesers or whatever ingredients you want to add.