Melt marshmallows with 1/4 cup milk in saucepan over low heat. Stir occasionally till smooth. Chill until slightly thickened; mix until well blended. Gradually add marshmallow mixture to softened cream cheese, mixing until well blended. Add sugar, chocolate, and 1 tbsp milk to 1 cup of cream cheese mixture; mix well. Divide whipped cream in half. Fold half the whipped cream into the chocolate mixture and half into the the remaining cream cheese mixture. For each parfait, alternately layer each cream cheese mixture in parfait glasses. Garnish with chocolate sprinkles if desired.

(I usually start and end the layering with the light cream cheese mixture. This is simply because it's a nice contrast to have the chocolate sprinkles on the top against the light cream cheese mixture rather than the darker mixture.)