1In small bowl, mix cookie crumbs and butter. Press in bottom of ungreased 8-inch springform pan. Freeze 10 minutes.
2Spoon ice cream onto crumb crust; smooth top. Cover and freeze about 2 hours or until firm.
3In 1-quart saucepan, heat whipping cream, sugar and chocolate to boiling over medium heat, stirring constantly. Boil and stir about 30 seconds or until chocolate is melted; remove from heat. Stir in cinnamon. Continue stirring 3 to 4 minutes or until thoroughly mixed, glossy and slightly thickened.
4Remove dessert from freezer 15 minutes before serving. Run metal spatula along side of dessert to loosen; remove side of pan. Serve dessert with warm or cool sauce. Store dessert covered in freezer.