White Chocolate Lime Puddings

Sift together the sugar, cornstarch, and salt into a medium-size saucepan. Slowly whisk in the cream and the milk. Beat together the egg yolks and add to the melted chocolate. Whisk the chocolate mixture into the saucepan along with the lime zest. Heat over medium-high heat, stirring constantly, just until the mixture comes to a boil. Lower the heat to medium-low and cook, stirring constantly, for about 2 minutes, until the pudding thickly coats the back of a wooden spoon. Remove from the heat and stir in the butter and vanilla if using.

Pour the pudding through a sieve to remove any lumps. Spoon into six 4-to-6-ounce jars. Cover and refrigerate for at least 2 hours, until cooled and thickened. Serve chilled.