Heat a gas grill to medium high, or prepare a charcoal grill. If you're using whole allspice, grind it in a mortar and pestle to a fine powder. If you're using ground allspice, put it in a small mixing bowl. If you're using fresh bay leaves, toast them briefly to dry. Crumble the bay leaves and grind them in the mortar with the allspice. Add the thyme and grind a few times so the leaves release their essence. Add the paprika, cloves, nutmeg, salt, habanero, and garlic; crush or grind until well combined. Pat the rub all over the meat. Grill uncovered, turning just a few times, until the meat is springy when squeezed, 18 to 20 minutes, or until an instant-read thermometer reads 150 degrees F. (The USDA recommends 160 degrees F, but I like mine juicier.) Transfer the meat to a platter and tent with foil. Let rest for 10 minutes before serving.

Make an incision down the length of the tenderloin, cutting two-thirds of the way into the meat and stopping a few inches above the end where the tail narrows. Open the tenderloin like a book, pressing the meat with the heel of your hand to flatten it evenly. The tenderloin should be a uniform 3/4- to 1-inch thickness. Repeat with the second tenderloin. Pat the rub all over the meat. Grill uncovered until the meat is springy when poked, 12 to 15 minutes, turning halfway through cooking. Transfer to a platter and tent with foil. Let rest for 5 to 10 minutes before serving.