Grease 4 x 125ml ramekin dishes with a little extra reduced fat spread.
Place the self raising flour, sweetener, Biscoff spread, reduced fat spread, eggs and caramel flavouring in a medium mixing bowl. Beat together for 1-2 minutes using an electric whisk or wooden spoon until smooth and creamy.
Divide the mixture between the 4 ramekin dishes. Drop a teaspoonful of Biscoff spread into the centre of each.
Place all 4 ramekins on the microwave turntable, evenly spaced apart. Cover loosely with cling film and cook on high for 1 1/2 - 2 minutes. Check on the cakes after about a minute and continue cooking if needed. The cakes will be ready when they're risen and spongy but still runny in the centre. Leave to stand for 5 minutes, then remove the cling film.
Dust with a little icing sugar and serve at once. Serve alone, or with a swirl of reduced fat aerosol cream or a little custard.