1. Preheat oven to 375. Place pineapple wedges on a rimmed baking sheet. Stir together rum, brown sugar, and vanilla bean and seeds in a small bowl. Brush rum mixture onto pineapple. Dot pineapple tops with butter.

2. Roast until liquid has evaporated and pineapple has caramelized, about 30 minutes. Let pineapple cool slightly in dish on a wire rack. Serve warm or at room temperature topped with ice cream.