Always been a fan of espresso on ice cream (Toscanini's sweet cream w/ a shot, please).

But the folks at Kitchn are mixing it up a little: instead of hot 'spresso on cold vanilla, they advocate a shot of Scotch instead, with the liquor's alcohol softening the ice cream instead of the heat of the coffee.  Sprinke with a little espresso powder, and you're all set.