I asked my SW consultant about this the other day. A really yummy way to do it is to get the 'Splenda' Brown sugar mix, and use that. Preheat your oven;
Whisk 2 egg whites until they form peaks, and then gently stir in 1tbsp of the Splenda. Spoon onto greaseproof paper and cook on medium for about 30 mins. They work out as 1syn for ALL of them