Anyone know of a substitute for maple sugar?

The recipe said cane sugar could be used.

Try agave syrup, if you have it -- I've even found some that is maple-flavored.

According to ochef,com, "a cup of granulated or light brown sugar (or a combination of the two) and half a cup of maple syrup, remembering to reduce some other liquid in the recipe by about 1/4 cup." Hope that helps.