In a small mixing bowl or large liquid measuring cup, combine thawed raspberries, milk, and pudding mix. Use an immersion blender to blend together until smooth.

Add heavy cream to the mixture, stirring with a spoon to combine.

Taste the mixture and add sugar, if needed, stirring well to incorporate.

Pour the mixture into a Ninja Creami pint container and close the lid. Transfer to a level surface in your freezer for at least 24 hours.

Remove from freezer and take off the lid. Place pint into the outer bowl of the Ninja Creami and secure the outer bowl lid. Transfer bowl apparatus to the Ninja Creami machine, locking it into place.

Press the Ice Cream button and allow the cycle to complete.

Remove pint from machine and check the ice cream's texture. If it appears crumbly, insert it back into the machine and press the Re-spin button. If it's still crumbly after that, add a tablespoon of milk and Re-spin once more.

Create a well in the center of the ice cream that's about an inch wide and extends all the way to the bottom of the pint. Add chocolate chips to the well.

Return the pint to the machine and press the Mix-in button. Allow the cycle to complete to mix-in the chocolate pieces.