This is one of those projects that sounds kinda tricky, but I am not about complicated recipes and this one is actually really simple. Plus, it's something that can hang out on your bar cart for a while.
1 small jar (0.9 oz) whole allspice berries
1 cinnamon stick
1 cup light rum
1.5 cups of water
2/3 cup brown sugar
First you have to grind up the allspice berries in your mortar and pestle bowl, then pour them into a sealable jar. Then add in the rum. Let this sit for four days, shaking daily, then on the fifth day add in the cinnamon stick and let infuse for an additional 7 days, a total of 12 days of infusion.
After the 12 days of infusion are up, strain the mixture through a fine-mesh strainer, and then again through a coffee filter or cheesecloth to get the extra tiny bits out.
Next, heat the water and sugar over medium heat until the sugar dissolves. Let the syrup cool, then add in the dram mixture and return to your sealed container. Shake well and let it rest for at least 5 days before use.
Next step: Imbibe!