Cold, refrigerated dough is the secret to making delicious focaccia! Allowing the dough to rest 18 to 24 hours in the fridge will yield extra-pillowy and airy focaccia, though if you are pressed for time, you can make this start-to-finish in 3 hours. This 4-ingredient recipe requires only 5 minutes of hands-on time. Video guidance below! Adapted from the focaccia recipe in Bread Toast Crumbs. A few notes: Plan ahead: While you certainly could make this more quickly, it turns out especially well if you mix the dough the day before you plan on baking it. The second rise, too, takes 2 to 4 hours. If you are short on time and need to make the focaccia tonight: Let the mixed dough rise at room temperature until doubled, about 1.5 to 2 hours. Then proceed with the recipe, knowing the second rise will only take about 30 minutes.  You can use various pans to make this focaccia such as: two 9-inch Pyrex pie plates. (Use butter + oil to prevent sticking.)  One 9x13-inch pan, such as this USA pan — do not split the dough in half, if you use this option, which will create a thicker focaccia . A 13x18-inch rimmed sheet pan — this creates a thinner focaccia, which is great for slab sandwiches. As always, for best results, use a digital scale to measure the flour and water. I love SAF instant yeast. I buy it in bulk, transfer it to a quart storage container, and store it in my fridge for months. You can store it in the freezer also. If you are using active-dry yeast, simply sprinkle the yeast over the lukewarm water and let it stand for 15 minutes or until it gets foamy; then proceed with the recipe.  Flour: You can use all-purpose or bread flour here with great results. If you live in a humid environment, I would suggest using bread flour. If you are in Canada or the UK, also consider using bread flour or consider holding back some of the water. Reference the video for how the texture of the bread should look; then add water back as needed.