If you run out of molasses, you can substitute 1 cup of molasses with 3/4 cup sugar, 1 1/4 teaspoons cream of tartar, and 1/4 cup hot water or any other liquid used in the recipe. Alternatively, use honey, maple syrup or dark corn syrup instead of molasses.
Many times, if a molasses substitute is needed, the other spices in the recipe can compensate for its absence.
A cup of molasses can also be replaced with 3/4 cup brown sugar or 3/4 cup granulated sugar and 1/4 cup water. Brown sugar is nothing more than granulated sugar with molasses added, so it is a good substitute for pure molasses.