Pound cinnamon sticks with a hammer or meat tenderizer to make smaller pieces. In a clean coffee grinder or spice grinder, combine cinnamon stick pieces, cloves, and allspice, and grind into powder. Leave it in the grinder and set aside.
Grate nutmeg on a nutmeg grater or microplane, measure, and add to grinder. (Freshly ground nutmeg is much more “lofty” than the kind you buy in the store, and much more aromatic.)
Add ground ginger to grinder, and give everything a whirl to combine.
Store mix in a tightly sealed jar until ready to use.