Using an electric mixer, whip the cream and instant coffee in a large bowl until soft peaks form, 3-4 minutes. Add the sweetened condensed milk, Kahlúa (if using), vanilla, and salt. Whip until combined and fluffy. Fold in the brownie chunks. Transfer to a 9x5 inch loaf pan. Add dollops of fudge sauce, then gently swirl the fudge on top. Cover and freeze until firm, at least 6 hours.Let ice cream sit at room temperature 5–7 minutes, then scoop and enjoy!