Whip cream with brown sugar until nearly fully whipped. Add cold brew and stout and continue to whip thirty seconds.
Pour into a container of an ice cream maker and follow manufacturer's directions.
For coffee hot fudge sauce:
Combine fudge sauce ingredients and stir; warm at thirty second intervals.
If desired, sprinkle on serving with espresso granules.
Recipe Notes
May be served immediately for soft-serve style ice cream, or transfer to a freezer-safe container and let set overnight.
Ice cream will be hard after freezing; allow to soften for 5-10 minutes.