Combine 1 cup evaporated milk and chocolate in small saucepan. Cook over medium heat, stirring frequently, until chocolate melts and mixture is smooth. Beat eggs and sugar in large bowl until well blended. Beat in peanut butter until smooth. Stir in hot chocolate mixture. Stir in remaining 2 1/3 cups evaporated milk. Refrigerate until well chilled. Pour into ice cream freezer container and freeze according to manufacturer's directions. Makes about 2 quarts.