Combine the instant coffee, sugar and hot water in a mug, and using an electric beater or milk frother, beat until stiff peaks form in the coffee mixture.
In another bowl, combine the sweetened condensed milk, vanilla and salt, and stir until everything is mixed well. Fold in the coffee mixture.
In a freezer-safe mixing bowl, beat the cream until stiff peaks form, and fold in the coffee mixture.
Cover the mixture with plastic wrap, and freeze until the ice cream is solid.
Serve with your favorite toppings. (I used chocolate-covered espresso beans and a light sprinkling of the instant espresso powder.)