Core and slice the pineapple into 1-inch thick rings—this is best done on a cutting board with a sharp knife to ensure even thickness for uniform cooking. While you're doing this, preheat your grill to medium heat and lightly oil the grates with cooking spray to prevent sticking. Even thickness is crucial here because it ensures the pineapple will cook evenly on both sides without some rings burning while others remain undercooked.

In a small bowl, whisk together the melted butter, light brown sugar, ground cinnamon, and sea salt until fully combined and smooth. The mixture should be wet and spreadable. I like to make this glaze while the grill is preheating so it's ready to use immediately—there's no need to let it sit, and brushing it on cold pineapple helps it adhere better.

Brush both sides of each pineapple ring generously with the cinnamon-brown sugar mixture from Step 2, making sure to coat evenly. Place the rings directly on the preheated grill grates and cook for 2-3 minutes on the first side until you see deep caramelization marks and the sugar begins to caramelize slightly. Flip carefully and grill the other side for another 2-3 minutes. I find that letting the grill do the work—without moving the pineapple around too much—gives you those beautiful char marks and deeper caramelization that really brings out the pineapple's natural sweetness.

Transfer the grilled pineapple rings to a serving platter or individual plates while they're still warm. Scatter fresh raspberries around or on top of the pineapple, and finish with a few fresh mint leaves for brightness and visual appeal. Serve immediately while the pineapple is still warm and the caramelized sugar is soft.