It's warm enough in the Keys to grill outdoors year-round. In less temperate climates, you can use a grill pan to cook the pineapple. Leftover ice cream is a treat served over waffles for a Boxing Day brunch. Change the liquor and nuts to vary the flavor of the ice cream.
Cut pineapple lengthwise into 12 slices. Brush pineapple slices with butter. Add pineapple to grill rack coated with cooking spray; grill 2 minutes on each side or until thoroughly heated. Cool slightly.
Place 3 pineapple slices into each of 4 bowls. Top each serving with 1/2 cup Rum-Macadamia Ice Cream and 1 teaspoon coconut.