Meanwhile, in a small bowl, stir together the roasted peppers, onion, capers, parsley, pepper flakes and vinegar; set aside.

About 30 minutes before you are ready to shape and fill the dough, heat the oven to 450°F with a rack in the middle position.

Mist a 13-by-18-inch rimmed baking sheet with cooking spray, then line it with kitchen parchment. Mist the parchment, then dust with flour.

When the dough has doubled, turn it onto the prepared baking sheet. With the long edge of the baking sheet nearest you, use lightly oiled hands to press and stretch it into an even layer that covers the surface of the baking sheet; it’s fine if the dough doesn’t completely fill the corners.