Servings: 10 to 12 Pour gelatin into bowl. Add 2 1/2 cups boiling water to gelatin. Stir, until gelatin is completely dissolved, about 2 minutes. Spray pizza pan with non-stick cooking spray. Pour gelatin mixture into pizza pan. Put pan into refrigerator to chill until firm, about 3 hours. Remove pan from refrigerator when ready to serve. Put about 1 inch of warm water in sink. Carefully dip just bottom of pan into warm water for 15 seconds. Spread whipped topping over gelatin just before serving, leaving about 1 inch of space around outside edge of gelatin for pizza "crust". Top pizza with fruit, arranging fruit in whatever design you like. Cut pizza into wedges.