Combine flour, sugar, and salt in the bowl of a food processor. Pulse to combine. Add butter, and process just until mixture resembles a coarse meal, about 10 seconds.
With machine running, add 1/4 cup ice water in a slow, steady stream through feed tube. Drizzle in egg yolks, and process just until dough holds together without being wet or sticky, about 30 seconds. Test dough by squeezing a small amount together. If it is crumbly, add a bit more ice water.
Divide dough in half. Pat into discs, and wrap in plastic. Chill for at least 1 hour.
On "Martha Bakes," the egg yolks and ice water were combined in a measuring cup before being added, drop by drop, through the feed tube of the running food processor at the start of step 2.