In my quest to make my own fancy coffee at home, I've been trying various pumpkin-spice syrups. Here's one that stood up to refrigeration. It's the spice, not pumpkin, that gives the syrup the signature taste. That, and the brown sugar.
1 cup water
1 cup dark brown sugar (must be dark brown)
1/4 tsp each cloves and ginger
1/2 tsp nutmeg
1 tsp cinnamon
Bring to a boil, then cook over lower heat until the syrup is reduced by half. This takes 5 to 10 minutes. Allow to cool completely, then pour into a glass jar and refrigerate. This makes about 1 cup of syrup.