Add all ingredients to a Ninja Creami container and stir or whisk until combined.
Place lid on the Ninja Creami container and freeze for at least 24 hours.
Remove from freezer and process on ice cream setting. If needed, respin or add a splash of milk and respin (I did not need to do this).
Notes
Don't worry if the lemon pudding mix isn't completely mixed in (as you can see in the photos above). You want most of it mixed in, but the rest will get mixed in as the Creami processes the ice cream.
The ice cream has a nice creamy lemon flavor that I love. However, if you want a super vibrant lemon flavor, add ¼ teaspoon lemon extract to the ice cream base.
If you have leftovers, simply smooth out the top and put back in the freezer. You may need to reprocesses before serving again (I did).
This recipe will work in the Ninja Creami or Ninja Creami Deluxe. It makes 16 ounces liquid ice cream base.