In a large bowl, combine cookie crumbs and butter. Press into a 13-in. x 9-in. dish. Carefully spread ice cream over crust. Spread whipped topping over ice cream. Drizzle chocolate syrup on top; sprinkle with nuts.
Freeze until firm, about 2-4 hours. Remove from the freezer 15 minutes before serving. Yield: 16 servings.