QUICK TIP: It may be helpful to watch the tutorial video in this recipe post before starting! YEAST: Whisk 2-1/4 tsp. yeast, 1 tbsp. honey, and 2-1/2 cups warm water in a medium bowl and let sit 5 minutes (It should look creamy/foamy after 5 minutes (see photo). (If not, your yeast is dead and you'll need to begin again. Either the yeast is dead or the water was too hot.)
(OPTIONAL) HERBED OIL: Skip this step and use regular olive oil for a plain focaccia bread. Otherwise, prepare this herbed oil for an herbed bread. In a small pot, add 6 tbsps. olive oil, 2 tsp. minced garlic, 1 tbsp. thyme, 1 tbsp. rosemary, and 1/4 tsp. black pepper. Place the pan over lowest heat setting and cook, stirring occasionally, for 5 to 10 minutes or until fragrant, but don't brown/burn the garlic! Set aside to cool.
DOUGH: In a very large bowl (that will fit in your fridge) add 5 cups all-purpose flour (Note 2) and 1 tbsp. fine sea salt and mix with a rubber spatula until a shaggy dough forms and no dry streaks of flour remain. Using the spatula, gently press the dough to one side of the bowl and pour in 4 tablespoons of the herbed (or plain) olive oil. Using both your hands, pick up all the dough (it's very sticky and wet!) and turn it around twice to fully coat in oil.
OVERNIGHT RISING TIME: Cover oiled dough with plastic wrap and chill in the fridge until dough is doubled in size (it should look bubbly and be wobbly), at least 8 hours and up to 24 hours. We highly recommend chilling overnight (better flavor!) but if you want to bake right away instead of chilling in the fridge, see Note 3. Pull out 3 tablespoons butter to set at room temperature overnight so it is very soft in the morning.
PREP PAN: See Note 1 to decide what pan you want to use. We want a really well-greased pan so we can easily remove the bread -- using your hands rub 1 tablespoon softened butter to generously grease the pan and then also lightly spray with cooking spray. Drizzle in 1 tablespoon of herbed or plain oil. Using your hands smooth oil evenly across bottom of pan.
2ND RISING TIME: Remove dough from the fridge and holding a fork in each hand, gather up the dough farthest from you and lift it up and over the center of the bowl. Give the bowl a quarter turn and repeat the process. Repeat 2 more times for a total of 4 times. Gently dump the dough into the prepared pan. Use a spatula to scrape any leftover oil right on top of the dough. Don't spread dough out at all, just let it be. Let dough rise, uncovered in a dry/warm spot (like on top of a preheating oven). Let rise until doubled in size about 1-1/2 up to 3 hours. (Move somewhere warmer if it isn't rising.) You'll know the dough is ready when if poked, it springs back slowly leaving an indentation (if it springs back quickly, it isn't quite ready).
BAKE: Place a rack in middle of oven; preheat to 450 degrees F (230 degrees C). Lightly oil your hands with about 1 teaspoon oil. Gently press/stretch dough to fill pan. If it resists, let it stand another 10 minutes. Dimple focaccia all over with your fingers, creating deep depressions in the dough (hit your fingers all the way to the bottom of the pan). If making plain focaccia, drizzle with remaining 1 tbsp plain oil (do not add extra herbed oil on top here because garlic will burn on top). Bake focaccia until puffed and golden brown all over, about 20–30 minutes in the 13x18-inch pan or 25-35 minutes in the 9x13-inch pan. Remove from oven and let stand for 10-15 minutes (steam is still cooking the bread so resist the urge to cut in). For herbed focaccia, right out of the oven, use a pastry brush to brush on the last 1 tablespoon of herbed oil.
TOPPING: Hold off on this last step until you're ready to serve the focaccia: (This is for the plain focaccia only) Melt the remaining 2 tablespoons butter in the microwave. Use a pastry brush to brush this melted butter only over what you'll be eating. If desired lightly sprinkle with sea salt. Cut into squares and enjoy warm! If you want this bread for sandwiches, cut into squares then use a sharp serrated knife to cut the squares in half widthwise.
STORAGE: Focaccia is best eaten the day it's made -- so good right out of the oven! It doesn't store especially well at room temperature beyond a day, but keeps well in the freezer. Slice it into pieces, tightly wrap pieces in plastic wrap then store wrapped pieces in a large freezer-safe bag or container. Freeze for up to 3 months. Reheat, unwrapped on a baking sheet in a 300 degrees F (150 degree C) oven.