Spray a 9"x9" pan with nonstick cooking spray, then spray the inside of a heavy large saucepan.
In the prepared saucepan, combine sugar, cream, butter & syrup, then cook over medium heat until sugar dissolves & mixture comes to a boil, stirring freuently. Re-incorporate any sugar crystals that accumulate on the sides of the saucepan.
Attach a candy thermometer to side of pan, making sure bulb is submerged in sugar mixture, BUT NOT TOUCHING BOTTOM OF PAN!
Comtinue cooking about 6 minutes or until sugar mixture reaches soft-ball stage (234 degrees F) on candy thermometer, stirring frequently.
Remove from heat & let stand 10 minutes ~ DO NOT STIR!
Add white chocolate & vanilla, then stir until chocolate is melted & mixture is smooth, about 1 minute.
Stir in cherries & walnuts, then spread evenly in prepared pan.
Score into 64 squares while fudge is still warm.
Refrigerate until firm, then cut along scored lines, separating into squares.