1/2 pound (2 sticks) unsalted butter, chilled, cut into small pieces
2 egg yolks
1 or 2 tablespoons heavy cream
In a food processor fitted with the steel blade, combine the flour and sugar. Add the butter and process until the texture resembles fine meal.
In a small bowl, whisk together the yolks and 1 tablespoon of the cream. Scrape into the machine and process until a ball begins to form, using the additional tablespoon of cream, if necessary. Remove the dough from the machine, and on a lightly floured surface, press down into a circle.
Wrap in plastic wrap and refrigerate for at least 1 hour.