Preheat oven to 350°F. Stir sugar and water in heavy medium saucepan until slightly dissolved. Without stirring, cook on medium heat 8 to 10 minutes or until sugar turns golden brown. Immediately pour into 9-inch round cake pan. Wearing oven mitts, quickly swirl and tilt pan to coat bottom and sides of pan with caramelized sugar. Place pan in large shallow baking pan. Let caramelized sugar stand at room temperature to cool and harden slightly.
Place milks, pumpkin, cream cheese, eggs, pumpkin pie spice and vanilla in blender container; cover. Blend on medium speed until smooth. Pour over caramelized sugar in pan. Pour enough hot water into baking pan to come halfway up side of cake pan.
Bake 40 to 45 minutes or until knife inserted in center of flan come out clean. Cool slightly. Carefully remove pan from water. Cool completely on wire rack.
Refrigerate 3 hours or overnight. Carefully run knife around flan to loosen from pan. Invert onto serving plate. Gently remove cake pan.