Melt chocolate in the top of a double boiler or in the microwave; set aside. In a bowl of an electric mixer, beat 1 cup whipping cream until soft peaks form. In the large bowl of an electric mixer, beat cream cheese for about 3 minutes or until light and fluffy. Add corn syrup, rum, cinnamon, ginger and vanilla. With the mixer on low speed, slowly pour in melted chocolate, scraping the sides of the bowl several times; beat until combined. Add remaining 1/4 cup cream and beat until thoroughly combined. Fold whipped cream into chocolate mixture. Divide equally between 8 small wine glasses and chill for at least 4 hours. Garnish with whipped cream and shaved chocolate before serving, if desired.