Brew your coffee extra strong and then place 1 C in the refrigerator until thoroughly chilled.
Pour coffee into a small pot and sprinkle the gelatin over it. Let stand for 5 minutes.
Move pot onto the stove and cook over a very low heat just until the gelatin is completely dissolved. Remove from heat.
In another bowl combine milk, sugar and vanilla.
Slowly stir or whisk coffee/gelatin mixture into the milk mixture.
Whisk in Cool Whip (it will first break into lumps and then as you whisk it will dissolve).
Refrigerate until firm.
Serve cold with additional Cool Whip on top.