Combine egg yolks, sugar, and salt in a mixing bowl; stir well. Gradually add half and - half, stirring constantly. Stir in coffee and vanilla.
Pour mixture evenly into six 4 - ounce oven proof pots de crème or custard cups; cover. Place cups in a 13- x 9- x 2-inch baking pan; add hot water to a depth of 1 inch.
Bake at 325° for 30 minutes or until a knife inserted between center and edge comes out clean. Remove cups from pan; cool to room temperature. Chill. Top with whipped cream.