i was thinking of using honey instead. Honey is better then sugar because it is less refined. It has slightly less calories then sugar, and is denser so it should have a stronger sweeter flavour then the sugar.
That recipe says about 40grams honey per quince which is about 136calories per quince, 1 whole quince has 32 cals, if i add a teaspoon of light spread 14cals, it would be about 90cals per half a quince
might add some vanilla in there too. I can't wait to have it on my so good ice cream!!! or in my porridge!!