Add the softened cream cheese and granulated sugar to a mixing bowl. Whisk until smooth.
Pour in the heavy cream, whole milk, and vanilla extract. Mix until evenly combined.
Gradually whisk in the dry cake mix until the base is smooth and free of dry pockets
Pour the mixture into a Ninja Creami pint container without exceeding the maximum fill line
Freeze the pint on a level surface for about 24 hours, or until completely solid
Place the frozen pint into the Ninja Creami outer bowl according to your machine's instructions
Select the Ice Cream setting and process until creamy
If the texture looks crumbly, use the Re-Spin function. Add a small splash of milk first if the mixture still looks too dry.
Add the rainbow sprinkles and use the appropriate Mix-In setting to distribute them
Serve immediately with additional sprinkles if desired.
