This lush dessert tastes like a lemon meringue pie without the crust.
In a medium saucepan (off heat), whisk yolks, 1 cup sugar, cornstarch, lemon zest, salt, and 1/2 cup of the milk until completely smooth; gradually whisk in remaining 3 cups milk.
Place saucepan over medium heat; bring to a gentle simmer, whisking occasionally (mixture will thicken when it reaches a simmer). Remove from heat; whisk in lemon juice.
Pour mixture through a fine-mesh sieve into a medium bowl. Divide evenly among serving dishes; refrigerate, uncovered, until chilled, about 1 1/2 hours. (To store overnight, cover dishes tightly with plastic once pudding has chilled.)
To serve, whip cream with remaining 2 tablespoons sugar until soft peaks form. Spoon over puddings; garnish with extra lemon zest, if desired.