Preheat the grill to low heat. Cut the top (called the crown) and bottom off the pineapple. Then, cut the pineapple into 10 wedges or whatever shape you want.
Mix the brown sugar, ground cinnamon, and cayenne pepper together on a large plate. Depending on how big your pineapple is and whether you cut off the rind, you may need to mix up more of this coating.
Coat the pineapple with the brown sugar mixture.
Grease the grill grates, add the pineapple spears, and cook for 8-10 minutes, flipping them over occasionally, until the pineapple softens and the coating caramelizes.
Video
Notes
Store leftovers in an airtight container in the fridge for 2-3 days. Reheat in the microwave for 10-20 seconds.