Mix sugar and water in glass measure. Microwave, covered, on high power 2 minutes, until sugar dissolves. Stir in butter.
Mix cornstarch, milk and half-and-half in bowl. Add to sugar mixture. Cover with vented plastic wrap. Microwave on high 6 minutes, stirring once halfway. Add vanilla. Pour in dishes. Chill 1 hour. Serve with whipped cream. Whipped Cream: Beat 1/2 cup cream until foamy. Add 1/2 teaspoon vanilla. Beat in 1 tablespoon confectioners sugar until soft peaks form.