What can I use in place of molasses ?

you could make a syrup out of brown sugar.

Lyes also makes another product called 'treacle' it has the same consistency and color as molasses if not darker

You could probably substitute any thick, liquid sweeter--even Aunt Jemina's or the dreaded corn syrup--BUT you will not get the dark color and the flavor will not be as rich. Sorghum would be the best substitute to retain color and flavor. Barley syrup might be a good choice--and there is alway's Lyle's Golden Syrup.

Maple Syrup.

I often sub honey for molasses.

What are you making?