In a mixing bowl or the pint container, whisk together the 1 1/4 cup whole milk, 1/2 cup heavy cream, 2-3 tbsp dry vanilla ice cream mix, and 2-3 tbsp granulated sugar until everything is well mixed and the sugar is fully dissolved.
Pour the blended mixture into the Ninja Creami pint container, secure the lid tightly, and freeze for 24 hours.
Once the mixture is completely frozen, remove the pint from the freezer, take off the lid, and place it in the Ninja Creami. Select the "Gelato" function and churn until the gelato reaches a creamy consistency.
In the last minute of churning, sprinkle in the 1/4 cup semi-sweet chocolate chips or chopped chocolate to create the signature stracciatella texture.
Enjoy the gelato immediately for a soft and creamy treat, or return it to the freezer for a firmer texture.