Cut the room-temperature butter repeatedly and vigorously with the pastry knife.
The dough is ready to roll out when it stops sticking to the sides of the mixing bowl.
Roll on wax or parchment paper and cut across.
For variation, press against sprinkles or coarse sugar. Bake at 350F for 11 minutes if you like them pale, and up to 17 minutes if you like them dark, on an ungreased cookie sheet.
Delicious with tea or tisane.