During the whole mixing process, scrape down the sides of the bowl as needed.
Beat everything but the egg and flour together until smooth.
Add the egg and mix until fully incorporated, approx 1 minute.
Slowly sift in the flour, and mix on low until fully combined, approx 1 minute.
Form a ball, wrap in plastic, refrigerate for 2-3 hours.
Preheat oven 375F
Roll even-sized balls, place 2" apart on a baking sheet.
Press flat with a fork vertically and horizontally to make a grid pattern.
Bake 10 minutes, or until golden brown.
Remove from oven, let rest 5 minutes before transferring to a cooling rack.