In a large mixing bowl, whisk together the flour, sugar, and salt. Using your hands, press the butter into the dry mixture. Do this by pushing each large piece of butter in between your thumb and index finger. This will sort of flatten out the butter pieces and break them up. The butter pieces should be the size of walnut or pecan halves.
Working slowly, add the ice water to the dry mixture, one tablespoon at a time, mixing well after each addition (about 1 minute). Dough should just barely stick together when pressed together firmly with both hands (you will not use all of the water, this is ok!).
Divide dough in half, pat into a round disk or small square, sprinkle with a few drops of water, and wrap tightly in plastic. Chill in fridge for at least 1 hour, if not longer, preferably overnight.
When ready to roll out, lightly dust work surface and rolling pin with flour. Roll one batch of dough into a rectangle that is 1 inch larger on all sides than your jellyroll pan. Place the first batch of rolled dough in the pan and prick with a fork. Place in fridge to chill.
Roll out the second crust to another rectangle of the same size and place on cookie sheet or cutting board lined with parchment. Place in fridge to stay cool while you prepare the filling.