Heat oven to 350. Heat chocolate chips and half and half over medium heat, stirring constantly until chocolate is melted and mixture is smooth; cool slightly. Beat eggs, sugar and salt; gradually stir into chocolate mixture.
Pour into 8 ungreased ovenproof pots de creme cups or 8 ungreased custard cups. Place cups in a rectangular pan. Pour boiling water into pan to within 1/2 inch of tops of cups. Bake 20 minutes. Remove cups from water; cool slightly. Cover with plastic wrap and refrigerate at least 4 hours but no longer than 24 hours.
Beat whipping cream and powdered sugar in chilled small bowl until stiff. Top each serving with sweetened whipped cream. Garnish with chocolate mints if desired.