1/4 cup firmly packed dark brown sugar
1/4 cup dark rum
3 tablespoons vegetable oil
2 tablespoons apple cider vinegar
1 bunch scallions (white and green parts), roughly chopped
1 Scotch bonnet chile, stemmed, seeded, and minced
5 cloves garlic, chopped
1 tablespoon freshly grated peeled ginger
2 teaspoons ground allspice
1 teaspoon pumpkin pie spice
4 boneless, skinless chicken breast halves (about 11/4 pounds), cut into large cubes
1 bunch scallions (white and green parts), cut into 2-inch pieces
1/2 fresh pineapple, peeled, cored, and cubed
Kosher salt
6 grilled pita bread, for serving (1 pita per serving)