This is the frozen key lime pie that ends up all over Jack Nicholson’s face in the film adaptation of the novel “Heartburn,” Nora Ephron’s thinly veiled recounting of her disastrous marriage to Carl Bernstein. It is very easy to make, and the large amount of key lime juice guarantees a tart, impressive flavor. We recommend eating it, though, not using it as a weapon. —Jennifer Steinhauer
