Step 1

Pour protein shake into a Ninja Creami pint container, being careful not to exceed the max fill line on the pint.

Step 2

If using, add sweetener to taste and stir to dissolve.

Step 3

Close lid on the pint container and place on a level surface in your freezer for at least 24 hours.

Step 4

Remove pint from freezer and take off lid. Place pint container into the outer bowl apparatus, locking the outer bowl lid into place.

Step 5

Secure the outer bowl apparatus into the Ninja Creami machine. Press the Lite Ice Cream button to process the pint.

Step 6

Remove the pint from the machine and check the texture of the ice cream. If it appears crumbly, reinsert it into the machine and use the Re-spin button to process again. If it's still crumbly, add a tablespoon of milk and Re-spin again.

Step 7

Optional: If you're using a mix-in, create a well in the ice cream that's about 1/2-inch wide and extends to the bottom of the pint. Add mix-in pieces to the well and insert the pint back into the machine. Use the Mix-in function to incorporate.