Toast the allspice, pepper, nutmeg, and cinnamon in a dry pan until fragrant over medium high heat. Use smell and sight as cues rather than relying on a set amount of time. For me this took about 8-9 minutes on an induction cooktop using a 10 in. carbon steel pan. DO NOT heat these to smoke point. If they start smoking you're done.
Break up the cinnamon and nutmeg berry into more manageable pieces using a mortar and pestle, molcajete, or with the flat of your knife. We do this so that the spice grinder can more uniformly grind the spices.
Let all of the spices cool for 10 minutes.
Blend all of the spices in spice grinder to a fine powder.
Remove the root ends and roughly chop scallions into 3 inch pieces.
Blend ground spices, the aromatics, and wet ingredients in a blender until relatively smooth. No more than 2-3 minutes depending on the strength of your blender. You are looking for a paste-like consistency that is thick enough to adhere to meat but not so clumpy it can’t be spread.
You can add 1 to 2 teaspoons of salt at this point or add no additional salt. I do not add additional salt because I add salt to whatever I’m marinating when I apply the jerk marinade to it.
This will keep comfortably in the fridge for 7 days in a non reactive container (deli cup, glass jar, Tupperware, pyrex etc.). Any marinade not used within this time frame should be frozen. This will last in the freezer at least 6 months or longer.