why not switch to low carb baking ? the results are just as nice, although the ingredients are more expensive. worth it though, if it stops the 'torture' and allows you to have some.
having said that, i am afraid i am much less kind than you
i am happy to do stuff for people, but not happy to have expectations laid on me. so i would probably smile sweetly and say 'sorry, not in a position to bake those cakes anymore. i could bring something low carb, or make a financial donation instead...?'
People never seem to object.