Put the marshmallows in a big microwave safe bowl (I have an8 cup Pyrexthat is perfect for this)
Heat for 1-2 minutes, until soft and puffy.
Whisk the soft marshmallows with 1/2 cup soy creamer until smooth. You may have to return the mixture to the microwave for another minute or so to get the marshmallows to fully melt into the creamer.
Add the remaining 2 1/2 cups of creamer, oil, and grenadine syrup. Whisk until smooth and the marshmallows are all melted.
Cool the mixture down in the freezer or refrigerator before pouring into an ice cream maker to freeze. I have a Cuisinart that is wonderful.
Don’t add the cherries and chocolate into the ice cream until it has fully frozen in the ice cream maker. Then just mix the chocolate and cherries in by hand. If you try to add them in while the ice cream maker is running, the volume will be too great and your ice cream maker will overflow.