Pour the almond milk, half and half, cottage cheese, allulose, marshmallow flavor oil, and guar gum into a small blender and blend until all ingredients are fully combined. Pour the mixture into a Ninja Creami container.
Freeze on a level surface for 24 hours. Your freezer should be between 9 and -7 degrees Fahrenheit.
Process the Ice Cream
After 24 hours, remove the Ninja Creami container from the freezer. If there is a large bump in the ice cream, melt or scrape the large bump so that the top is level.
Place the Ninja Creami container into the outer bowl of the Ninja Creami and then process on "LITE ICE CREAM."
If the ice cream is dry or crumbly looking (like sand), pour in a tablespoon or two of half and half and then re-spin. If the ice cream looks more like little balls of ice cream, re-spin without adding liquid. You may have to respin a couple of times.
Dig a well down the center of the ice cream, pour in the marshmallow fluff, cover the fluff with the ice cream so less of it sticks to the lid, and process on "MIX-INS."
Notes
Are there marshmallows in marshmallow ice cream?
No, there are no actual marshmallows in this recipe. Instead, Lorann’s marshmallow flavor oil and marshmallow fluff is used. Actual marshmallows do not provide a lot of flavor and they get quite hard when added as mix-ins.
What happens to the marshmallow fluff when it is mixed into the ice cream?
The marshmallow fluff gets partially mixed into the ice cream base while also staying together in little ribbons. So, you get the extra flavor of marshmallow while also getting little pieces of marshmallow fluff throughout.
Is the marshmallow fluff hard to mix-in?
Marshmallow fluff is a little tricky to mi-in. If you add the fluff to the well down the center of the ice cream, put the lid on, and process, you will end up with a frozen blob of marshmallow on the lid and paddle. To help with this, put the marshmallow fluff in the well and then cover it with ice cream before putting the lid on and processing. If you bury the fluff, it mixes in better.