MELT CHOCOLATE BASE; combine coffee or espresso powder and hot water in small bowl. Let stand until dissolved, about 5 minutes.
Microwave chocolate, sweetened condensed milk, and coffee mixture in microwave safe bowl, stirring every 10 seconds, until chocolate is melted, about 1 minute. Stir in vanilla and salt. Let cool.
MIX AND FREEZE; With electric mixer on medium-high speed, whip cream to soft peaks, about 2 minutes. Whisk one third of whipped cream into chocolate mixture. Fold remaining whipped cream into chocolate mixture until incorporated.
Freeze in airtight container until firm, at least 6 hours or up to 2 weeks. Serve