Julia's Chocolate Tart Dough

Makes enough for six 5-inch tartlets or one 10-inch tart. Imagine the best crust you can: butttery, flaky, and just a little sweet- and now imagine that it's chocolate through and through. Use this crust to fill the extrabagantly rich Chocolate Truffle Tartlets (recipe also posted), to fill with pastry cream or creme fraiche and top with fruits, or to create a grown-up ice cream pie, filled with superior ice-cream and drizzled with a bittersweet chocolate sauce. From Julia Child's "Baking with Julia".

• Ready In: 45 mins
• Yields: 1 10inch tart

Ingredients

• 1 1⁄4 cups all-purpose flour
• 1⁄4 cup  unsweetened cocoa powder, preferably dutch-processed
• 1⁄4 cup sugar
• 1⁄4 teaspoon salt
• 1⁄2 cup  cold unsalted butter, cut into small pieces
• 1  large  egg yolk
• 1  tablespoon  ice water

Directions

1. To make dough in food processor fitted with metal blade: put the flour, cocoa, sugar and salt in work bowl and pulse just to blend.
2. Add butter and pulse 8-10 times, until pieces are about the size of small peas.
3. With machine running, add yolk and ice water and process, in short bursts, until JUST crumbly- don't overwork it!
4. Turn it out onto the work surface and, working with small portions, smear the dough across the surface with the heel of your hand.
5. Gather the dough together and shape it into a rough square.
6. Pat it down to compress it slightly, and wrap in plastic.
7. Chill until firm, at least 30 minutes.
8. The dough can remain in the refrigerator for 3 days, or it can be wrapped airtight and frozen for a month.
9. Thaw the dough, still wrapped, overnight in the refrigerator before rolling it out.
10. Cook's note: When I made this, I stuck the dough in the freezer to chill, then promptly forgot about it.
11. 4 hours later, when I remembered to pull it out, it was frozen solid.
12. I pulled out my box grater and grated it directly into the pie pan.
13. It worked beautifully, no roling involed: just patted it all down into place.