Ingredients:

• 1/2 cup extra-virgin olive oil, divided, plus more for greasing hands
• 2 1/2 cups warm water (about 110°F)
• 1 tablespoon honey
• 2 1/2 teaspoons active dry yeast (from 1 [1/4-ounce] package)
• 5 cups (about 21 1/4 ounces) all-purpose flour
• 3 1/2 teaspoons kosher salt
• 3 tablespoons fresh rosemary leaves
• 1/2 tablespoon flaky sea salt (such as Maldon)

Cooking Instructions:

1. Grease a large bowl with 1 tablespoon of the oil; set aside. Whisk together warm water, honey, and yeast in a separate large bowl until combined; let stand until foamy, about 5 minutes. Add flour and kosher salt; stir with a wooden spoon until just combined. Drizzle 4 tablespoons of the oil over top, and stir with the wooden spoon to incorporate. Transfer dough to greased bowl; cover tightly with plastic wrap, and refrigerate at least 12 hours or up to 18 hours (dough will double in size before it is ready).
2. Remove bowl from refrigerator; let stand at room temperature until dough has puffed up and doubled in size, about 2 hours.
3. Brush 2 tablespoons of the oil in bottom and up sides of either a 13- x 9-inch metal baking pan or a 12-inch cast-iron skillet. Grease your hands with oil. Uncover bowl; with dough still in bowl, lift and fold over the back edge of the dough from the underside, and bring it towards you in the center. Rotate dough 45 degrees. Repeat folding and rotating process until all the edges of the dough are folded into the center, 4 to 6 times. (The dough will noticeably deflate.) Turn dough into prepared pan, and spread gently with greased hands to fill the pan. It’s OK if dough doesn’t reach all corners; it will as it continues to expand at room temperature. Cover pan tightly with plastic wrap, and let stand until dough puffs slightly and reaches corners of the pan, about 1 hour.
4. Preheat oven to 450°F. Remove plastic wrap, and sprinkle dough with rosemary leaves. Using greased hands, dimple dough all over with fingers. Drizzle with remaining 1 tablespoon oil, and sprinkle with flaky salt. Let stand at room temperature until dough is puffed up, about 15 minutes.
5. Bake focaccia in preheated oven until golden brown, 20 to 25 minutes in the baking pan or 35 minutes in the cast-iron skillet. Immediately remove focaccia from pan, and transfer to a wire rack. Let cool completely, about 1 hour. Cooled focaccia may be wrapped in plastic wrap and stored at room temperature up to 3 days.