In a food processor with the blade attachment, pulse the butter and sugar a few times (about 3 times).
Add the flour and salt and pulse again until the butter is mostly pea-sized or slightly bigger (about 5 pulses).
Add the egg yolk and heavy cream, pulse a few times then let the mixer go until the dough comes together into a ball.
Dump the dough out onto a clean counter and gently knead the dough a few times before forming into a flat disc. Wrap in plastic and refrigerate for at least 30 minutes and up to 5 days (freeze for up to 6 months, thawing in the fridge 24hrs). Let dough sit on the counter 10-15 minutes before rolling.
Recipe by Eat Some Wear Some at https://eatsomewearsome.com/pecan-pie/