Zest and juice the limes and add the zest and juice along with cottage cheese, milk, sugar, and vanilla extract to a blender. Blend until smooth.
Pour mixture into Ninja Creami container and freeze on a level surface in the freezer for 18-24 hours.
Remove from the freezer and run warm/hot water on the outer edge of the container for 30 seconds.
Process on the Light Ice Cream Setting. Respin if needed.
Add crushed graham crackers and stir to combine (or use the mix-in feature on the Creami).
Notes
I always like to run warm/hot water along the outer edge of my Creami container for 30 seconds before processing. This helps the outer layer to thaw and get properly incorporated.
If your Ninja Creami is crumbly, add a splash of milk and respin. if it's just not soft enough, simply respin. Needing to do this or not may depend on your freezer temperature.
If your ice cream is too soft after processing, add back to the freezer for 20-30 minutes and scoop out and enjoy.
If you have leftovers, smooth out the top and return to the freezer. You may need to process again before enjoying.