Coffee Stracciatella

Combine cream, milk, salt, and ¼ cup sugar in a medium saucepan. Scrape in seeds from vanilla bean; add pod. Bring mixture just to a simmer, stirring to dissolve sugar. Remove from heat. If using vanilla bean, cover; let sit 30 minutes.

Whisk egg yolks and remaining ¼ cup sugar in a medium bowl until pale, about 2 minutes. Gradually whisk in ½ cup warm cream mixture, then whisk yolk mixture into remaining cream mixture. Cook mixture over medium heat, stirring constantly, until thick enough to coat a wooden spoon, 2–3 minutes.

Strain custard into a medium bowl set over a large bowl of ice water. Stir in espresso powder until dissolved. Let cool, stirring occasionally. Process custard in an ice cream maker according to manufacturer’s instructions. Once custard is frozen to desired consistency in ice cream maker, gradually pour in chocolate; process until ice cream is flecked with chocolate, 2 minutes longer.