Put all of the ingredients (except the carrot and nuts) into the Ninja CREAMi pint container and mix well.
Put the lid on the tub and freeze for 24 hours.
Remove the lid and put the frozen pint tub into the outer bowl and put on the outer bowl lid. Put into the Ninja Creami machine and set to the Frozen Yogurt setting and spin.
One spin should be sufficient to achieve the perfect texture. If it is still crumbly, re-spin 1-2 times.
Use a long thin spatula or palette knife to make a well in the centre of the ice cream. Fill the well with the carrot and nuts.
Put the tub back into the outer bowl and replace the lid. Return to the machine and process on the Mix-In setting.
Notes
Use finely grated carrot rather than thick shreds. Fine carrot mixes in more evenly and gives a better carrot cake texture.
Pat the grated carrot dry with kitchen paper before adding it. Carrot contains a lot of moisture, and removing the excess helps prevent icy pockets.
Do not add the carrot and pecans before freezing. They are better added after the first spin so they keep their texture.
Make sure the base is frozen for a full 24 hours. If it is not fully frozen, the CREAMi machine will not process it properly.
Freeze the pint tub on a level surface. A flat frozen base spins more evenly.
If the ice cream is crumbly after the first spin, it is not ruined. This is common with lower-fat, high-protein CREAMi recipes. Re-spin once or twice, adding a splash of milk only if needed.
Do not overfill the mix-in well. Around 2-3 tablespoon of total mix-ins is usually enough for one pint.
For the creamiest result, use a thicker Greek yogurt and a protein powder you already like the taste of, as you will be able to taste it.