Put the flour, salt, and sugar into the food processor bowl. Give a quick pulse to mix the dry ingredients. Add in the butter cubes, trying to sprinkle them evenly around the bowl. Pulse again (approx. 15 times) until your butter is about the size of small peas. Remove the processor lid and sprinkle 4 teaspoons of ice water around the mixture. (You can add up to an additional 2 teaspoons if you need to). Pulse again until you see small dough bits.
Take 2 sheets of waxed paper and lay them out. Dump the dough bits out onto one of the sheets. Do a very short knead, just enough to bring the bits together. You will see butter clumps still - that's a good thing! Divide the dough ball in half. Wrap each half in a sheet of waxed paper and stash in the refrigerator for 30 minutes. The time in the refrigerator will hydrate the flour - don't skip this time.
Make sure you have a rack set in the center of the oven and preheat to 375°F.
Tart/Cake Pans: Grease the cake pans with the room temp butter and place them on a cookie sheet to make it easier to take them in and out of the oven. Jumbo Muffin Pan: Line 2 muffin cups with aluminum foil and then lightly grease the foil with room temp butter.
Take the crust from the refrigerator and roll out each into 6 inch rounds. Fill your pan of choice with the crust. Make sure you tuck the overhanging dough to the inside. If you are using a tart pan, make sure you press into the grooves. If using a muffin pan, you may have to pleat the dough a bit for a proper fit.
Prick the bottom of the crust with a fork several times; this is called docking. Place the crusts in the freezer for 15 minutes to firm them up a bit.
Remove the crusts from the freezer and line with aluminum foil, pressing it snug against the dough. Fill with pie weights; if you don't have pie weights, you can use dried beans or uncooked rice instead. Place in the oven to bake for 15 minutes. If using a muffin tin, fill the empty cups about halfway with water to keep your pan from scorching.
Take the pan out of the oven and remove the foil and weights. For partially baked crusts, return to the oven for 4-5 minutes, or until dry. For fully baked crusts, return to the oven for 8-10 minutes or until lightly golden brown.