For the mousse - In a large bowl whisk together pudding mix and milk. Let stand for 5 minutes to thicken.
Fold in the Cool Whip until blended. Spoon or pipe into the chocolate cups. Cover with a sheet of tinfoil and refrigerate until ready to serve. Just before serving top with a nonpareil candy, sprinkles, chocolate shavings, chocolate covered espresso beans or raspberries if desired.
For the chocolate cups - Place chocolate in a microwave safe bowl and microwave at 50 percent power in 30 second intervals until melted, mixing after each 30 seconds. Spoon 2 Tbsp. of melted chocolate in each silicone or paper cup. Use your basting brush and paint the inside of the cup to coat it entirely. Place the cups in the refrigerator on a baking sheet and chill for 15 minutes. Remove from the refrigerator and carefully remove the chocolate cup from the silicone or paper cup. Fill with mousse.