Preheat the grill to medium-high heat.
Remove the top and bottom from the pineapple, stand it upright, cut the skin off, removing the eyes, and slice the pineapple into 1-inch thick rings.
In a small mixing bowl, combine the brown sugar, melted butter, ground cinnamon, and a pinch of salt. Stir until well mixed.
Use a basting brush to coat each pineapple ring generously with the brown sugar mixture on both sides.
Once the grill is hot, place the pineapple rings on the grill. Grill for about 3-4 minutes on each side, or until grill marks form and the pineapple becomes tender.
Remove the grilled pineapple from the grill and serve immediately. Garnish with fresh mint leaves if desired.
For an added flavor boost, consider marinating the pineapple in the brown sugar mixture for 30 minutes before grilling.
Serve the grilled pineapple with a scoop of vanilla ice cream or yogurt for a delightful dessert combo.