On low speed, mix peanut butter, butter and both sugars in the bowl of an electric mixer fitted with a paddle attachment, until incorporated.
On low speed, add eggs and vanilla and mix until just combined.
Sift salt and flour together and add to the mixture, stirring on low speed. (Tip - Before you mix, cover your bowl losely with a large tea towel, ensuring the tea towel does not get pulled into the machine, to trap the flour inside and prevent spilling). Mix until the dough collects around the paddle attachment.
Roll your dough between two sheets of parchment paper and chill in the fridge for at least one hour. For a post on cookie thickness, see here.
Cut your cookie shapes out and re-roll as needed. Note that shapes which are re-rolled tend not to keep their shape as well, even if you follow all the correct steps. Keep your cookie shapes with most detail for the first round of cutting.
Place cookie shapes at least 1/2 an inch or 1 cm apart on a baking sheet lined with parchment paper.
Place tray(s) of cookies in a fridge or freezer until thoroughly chilled; at least one hour.
Bake at 350 degrees Fahrenheit for approximately 8-12 minutes. Larger shapes will need more time and smaller shapes less. Look for slightly golden brown edges.