Preheat oven to 425. In large bowl, mix pineapple, 2 T. melted butter, sugar, flour, lime zest and lime juice, tossing gently to mix. Pour into an 8 x 8 inch square baking pan. In medium bowl, mix oats, coconut, macadamia nuts, salt and remaining 6 T. melted butter, tossing gently. Spread over pineapple mixture. Bake until golden brown and bubbly, 20 to 30 minutes. Serve with coconut ice cream. or gelato if desired. Makes 1 eight inch cobbler.