Thoroughly mix the brown sugar, ground cinnamon, allspice, salt, and chili powder in a small bowl, making sure there are no lumps. Set aside.
Twist the top of the pineapple, and it should come off easily. Slice the top and bottom off the pineapple for a stable cutting base.
Set the pineapple upright and trim off the peel, working your way around the pineapple. Cut out any eyes or bits of the peel that remain.
Turn the pineapple up on its end, and slice it down the middle into halves.
Lay the halves cut-side down on the cutting board and slice them into quarters. Lay the pineapple wedges on their sides and slice off the core.
Preheat your grill to medium-high heat. (375-450℉/190-230℃)
Place the wedges in a baking dish or pan in a single layer. Brush them with the spice rub, covering every inch. Optionally, stick a skewer into each one like a lollipop stick for easier serving. The juiciness of the pineapple will dissolve the sugar.
When the grill is hot, place the pineapple wedges in it and cook them for 3-4 minutes per side or until charred and slightly caramelized. Flip them with a spatula to prevent breaking.
Take the wedges out of the grill and let them cool slightly before serving.
Enjoy as a side for pork, ham, chicken, or fish, or with vanilla ice cream for a decadent dessert.