If you have a large mixer, you can double the recipe for 40 tarts. Otherwise, make two batches to accommodate our Strawberry Tartlets recipe.
Pulse flour, sugar, and salt in a food processor to combine. Add butter; process until mixture resembles coarse meal, about 10 seconds. Add yolks; pulse. With machine running, pour ice water in a slow, steady stream through the feed tube until dough holds together, no longer than 20 seconds.
Divide dough in half and shape each into a square; wrap in plastic. Refrigerate at least 1 hour or up to 2 days, or freeze up to 1 month.