Preheat the oven to 350°. Butter four ½-cup ramekins and place them on a baking sheet.
Coarsely chop the chocolate and gently melt in a microwave-safe bowl, stopping and stirring at 30-second increments until smooth.
Combine the chocolate with the cream cheese and vanilla and mix with a rubber spatula till well combined.
Stir together the sugar and flour, and mix into the chocolate mixture until well combined.
Add the egg and mix until incorporated.
Divide the batter evenly between the ramekins.
Bake for 20 to 25 minutes, until the centers are set.
Cool slightly before serving.
May top with a dollop of whipped cream or vanilla ice cream and berries if desired.
