Cook 1/2 cup water and sugar in 4-qt. saucepan on medium-high heat 1 to 2 min. or until sugar is completely dissolved, stirring occasionally with wooden spoon. Bring to boil; cook 7 min. or until slightly thickened. (Do not stir.) Stir in nuts; cook 6 to 9 min. or until nuts are evenly coated with glaze, stirring constantly. (Glaze will appear dry.) Cook and stir 1 to 3 min. or until glaze melts and caramelizes.
Remove from heat; immediately stir in 1 Tbsp. drink mix.
Spread onto foil-covered baking sheet; cool. Break into clusters. Reserve 1/3 cup nut clusters for garnish.
Meanwhile, bring remaining water to boil.
Pour over petals in small bowl; let stand 10 min. Stir in remaining drink mix.
Stir undrained petals and remaining nut clusters into ice cream in large bowl until well blended. Spoon into 9x5-inch loaf pan. Freeze 2 hours. Unmold dessert just before serving.
Serve topped with COOL WHIP and reserved nut clusters.