Heat heavy cream and whole milk in a saucepan over medium heat until steaming, with small bubbles just starting to form around the edges. Visual cue: steam should rise consistently but the mixture should not boil.

Whisk egg yolks and granulated sugar in a bowl until smooth and slightly thickened. Visual cue: the mixture should look pale and ribbon easily from the whisk.

Slowly whisk the steaming cream mixture into the egg yolks in a thin stream to temper. Visual cue: the custard should stay glossy without scrambling.

Return the mixture to the saucepan and cook over medium-low heat, stirring constantly, until the custard reaches 175F. Visual cue: it should coat the back of a spoon and hold a line when you run a finger through.

Remove from heat and whisk in creamy peanut butter until completely smooth. Visual cue: no peanut butter streaks should remain.

Strain the custard through a fine mesh sieve into a clean container, then add vanilla extract and salt. Visual cue: the final texture should look silky and uniform.

Cool the custard over an ice bath, stirring occasionally until it is cool to the touch. Visual cue: the container should feel cold quickly and the custard should thicken slightly as it cools.

Refrigerate the custard at least 4 hours or overnight until thoroughly chilled. Visual cue: it should be cold throughout and pourable but noticeably thick.

Churn the chilled custard in an ice cream maker according to the manufacturer’s instructions. Visual cue: it should look like soft-serve and hold gentle ridges from the paddle.

Freeze the churned ice cream until firm. Visual cue: it should become scoopable with resistance and not feel like melted soft-serve.