For the raspberries: Bring the raspberries, sugar, and salt to a simmer in a medium saucepan over medium-high heat. Cook, stirring and pressing down on the berries occasionally until they have released their juices, about 5 minutes. Strain the berry mixture through a fine-mesh strainer, pressing on the solids to extract as much juice as possible. Discard the solids. Let the juice cool to room temperature.
For the chocolate pieces: Line a baking sheet with parchment paper. Melt the chocolate in a heatproof bowl set over a pan of boiling water, being careful not to let the water touch the bottom of the bowl. Stir constantly until just melted. Remove from the heat and pour the mixture into the prepared pan and freeze until firm, 10 to 15 minutes. Prepare the ice cream while the chocolate is setting. When the chocolate is firm, chop it into bite-sized pieces, and add to the ice cream immediately (it will start to melt as you chop it, so work quickly).
For the ice cream: In a large bowl, whisk the sweetened condensed milk, vanilla, salt, and raspberry juice until completely combined. In the bowl of a stand mixer fitted with a whisk, beat the cream cheese on medium until smooth. Turn the mixer to low and add the heavy cream in a slow steady stream, mixing until combined. Increase the speed to medium-high and whisk until stiff peaks form, 3 to 4 minutes. Add half the whipped cream mixture to the sweetened condensed milk mixture and whisk until completely combined. Using a rubber spatula, gently fold the remaining whipped cream mixture until no streaks remain. Add the chopped chocolate and mix to combine. Pour into a 9 in [23 cm] loaf pan or Pullman pan with a lid and freeze until firm, 6 hours, or covered, up to 1 week.
You will get about a 1/2 cup [120 g] of raspberry juice. A little more or a little less is okay; don’t put in more than 3/4 cup.