2 qts. whipping cream
4 lb. 4 oz. semisweet chocolate chips, divided
1 qt. plus 2-1/4 C. caramel topping, divided
3 T. vegetable oil
To prepare mousse, melt together cream and 2 pounds of the chocolate, stirring to blend smooth. Chill until cold. Beat in mixer until consistency of whipped cream. Pour into 12-inch x 20-inch steam table pan, spreading evenly. Cover with 1 quart of the caramel topping. Freeze firm.
To prepare topping, melt together remaining chocolate and the oil. Stir to blend smooth.
Cut frozen mousse into 1-1/2 inch x 4 inch bars. Place bars on wire rack over sheet pan. Ladle 1 ounce melted chocolate topping over each bar, covering top and sides completely. Transfer coated bars to another pan and freeze.
For each serving: Drizzle plate with 1/2 oz. warmed caramel topping. Arrange frozen mousse bar on plate.