1. Spray the pineapple slices with the cooking spray on both sides and rub with the dark brown sugar.

2. Beat the heavy cream with an electric hand mixer on high speed in a chilled medium bowl until it thickens. Add the confectioners’ sugar and beat until stiff peaks form. Beat in the rum until stiff peaks form. Refrigerate until ready to serve.

3. Heat a rimmed grill pan over high heat until very hot. In batches, add the pineapple to the pan and grill until seared with grill marks, turning once, about 3 minutes. (The pineapple can also be grilled on an outdoor grill over medium heat.) Transfer to a plate and let cool slightly.

4. For each serving, place 2 pineapple slices on a dessert plate. Top with a dollop of the rum cream, sprinkle with a tablespoon of coconut, and garnish with a mint sprig. Serve immediately.