Add all ingredients except the chocolate to a medium saucepan over medium low heat. Whisk just about constantly for 15 minutes, until thickened and smooth.
Add the chocolate and whisk until melted.
Pour the custard into 6-7 individual glasses or dishes and let cool to room temperature. Transfer to the refrigerator and chill for at least 8 hours or overnight.
To serve, top with a dollop of whipped cream and a coconut corn cracker.