You’ll have to use your judgment, but we would say don’t. The folks at Domino Sugar say you can substitute their "Brownulated" light brown sugar measure for measure with regular brown sugar in recipes, but - and it’s a huge but - because the moisture content is different it will produce "differences in texture as compared to recipes made with regular brown sugar."

If that unknown isn’t enough of a deterrent, Sharon Tyler Herbst, author of The New Food Lover’s Companion (Canada, UK) flat out says don't do it.