Line shallow pan with foil; set aside. Spread sugar onto bottom of small nonstick skillet; top with nuts. Cook on medium-low heat 5 min. or until sugar is completely melted and golden brown, tilting skillet to evenly distribute sugar if necessary. Stir until nuts are evenly coated. Immediately spread into prepared pan; cool completely.

Microwave tomatoes and dressing in microwaveable bowl on HIGH 3 min. or until tomatoes are slightly softened and dressing is heated through, stirring after 2 min.

Cover platter with spinach; top with tomato mixture, cream cheese, onions and nuts. Toss lightly before serving.