Heat oven to 400 degrees. Line a baking pan/sheet with parchment paper or foil. Place rings on baking sheet and drizzle with half of the melted butter and sprinkle with half of the brown sugar. Roast for 10 minutes.

Turn over with tongs and top with remaining butter and sugar. Bake until juices are bubbling and pineapple is light gold, another 5 to 10 minutes. Set on wire rack to cool.

Serve each ring with a scoop of vanilla ice cream and drizzle with juices left in the pan if desired.