Slightly thaw the chocolate ice cream until it is softened and can be easily scooped.
Add all ingredients into the bowl of an electric stand mixer.
Mix on low speed until all ingredients are evenly incorporated.
Put Rocky Road ice cream into a freezer-safe container and refreeze until firm, about 2 hours.
Notes
If you plan to use your own ice cream recipe to make the chocolate ice cream, you could add mix-ins right into your ice cream maker if your model allows it. Be sure to follow the ice cream maker's instructions and to use the correct blade for mix-ins.Remember to scale the mix-ins appropriately for the amount of ice cream you are making!