Combine 2 teaspoons each of salt and pepper, 1 teaspoon paprika, and granulated garlic in a small bowl. Pat steaks dry. Using a sharp knife, score one side of each steak in a crosshatch pattern, cutting only about ⅛ inch deep and spacing about ½ inch apart. Sprinkle steaks all over with the seasoning mixture, rubbing it into the scored side. Let steaks stand, scored side up, for 15 minutes.

Set a wire rack in a rimmed baking sheet. In a 12-inch cast-iron skillet, heat 1 tablespoon of oil over medium-high until barely smoking. Add the steaks scored side down and cook without disturbing until well browned, about 3 minutes. Flip the steaks and cook until the centers register 125ºF to 130ºF for medium-rare, about another 3-6 minutes. Transfer the steaks scored-side up to the rack and let rest for 15 minutes.

Meanwhile, in a small bowl, combine the capers, anchovies, grated garlic, and remaining 2 teaspoons paprika, then use a fork to mash to a smooth paste. Whisk in the vinegar, remaining 3 tablespoons oil, the Worcestershire, and the accumulated juices from the steaks. Stir in the parsley. Taste and season with salt and pepper.

Transfer the steaks of a cutting board and thinly slice on a diagonal. Place the slices on a platter and pour the vinaigrette over the steak, letting it rest for several minutes. Sprinkle with flaky salt, if using, and additional pepper.