Prepare an ice-water bath. Beat yolks, sugar, and salt with a mixer on high speed until pale yellow and thick, about 5 minutes.
Meanwhile, scrape vanilla seeds into a medium saucepan, and add pod, milk, and cream. Bring to a boil, then remove from heat.
Reduce mixer speed to low; gradually mix half the hot milk mixture into yolk mixture until just combined. Pour yolk-milk mixture into saucepan with remaining milk mixture. Cook over medium-low heat, stirring constantly with a wooden spoon, until thick enough to coat back of spoon and hold a line drawn by your finger, 5 to 7 minutes. Strain mixture through a fine sieve into a bowl. Place bowl in ice-water bath, and let stand, stirring occasionally, until chilled.
Creme anglaise can be refrigerated for up to 3 days. Gently whisk before using.