Place loaf pan in freezer. In bowl, using a fork, mash blackberries with sugar and let stand to macerate.
In large bowl, whisk together condensed milk and cocoa until smooth; whisk in Black Currant Flavour and salt. Fold in whipped cream.
In bowl, beat cream using an electric mixer starting on medium-low to medium-high until stiff peaks form. Fold one-third into cocoa mixture until no streaks remain; fold in remaining whipped cream.
Spoon half of ice cream mixture into the loaf pan; spoon half of the berry mixture over the top. Repeat with the remaining ice cream and blackberries. Freeze for at least 6 hours.
