In small bowl, combine crushed cookies and ½ cup softened butter. Press onto bottom of 13x9x2-inch baking pan. Spread softened ice cream over crust. Cover and freeze for 1 hour or until firm.
In medium saucepan, combine milk, ½ cup butter and chocolate syrup. Bring to boiling; reduce heat. Simmer, uncovered, for 5 minutes, stirring constantly.
Remove from heat. Cool completely. Pour over ice cream. Freeze for 1 hour or until firm.
Spread whipped topping over chocolate layer. Sprinkle with walnuts. Top with cherries. Cover and freeze for 1 hour or until firm.