Original recipe is from King Arthur. This is scaled from the original two-round thin focaccia recipe to fit a single 16" × 12" Grandma pizza pan.
Timing
| Phase | Time |
| Prep | ~25 minutes |
| Bake | 12 to 16 minutes |
| Total | ~40 minutes |
| Yield | One 16" × 12" pan |
Ingredients
Baker's percentages are relative to flour weight (200g). Toppings are not part of the dough formula and have no baker's percentage.
| Ingredient | Weight | Baker's % |
| '00' or Bread Flour | 200g | 100% |
| Water, warm | 122g | 61% |
| Extra-virgin olive oil | 14g | 7% |
| Kosher salt | 5g | 2.5% |
| Cow or buffalo milk mozzarella, torn into bite-size pieces | 107g | — |
| Flaky sea salt, for topping | to taste | — |
Instructions
1. Make the Dough
In a stand mixer bowl, combine the flour, water, olive oil, and salt. Using the dough hook attachment, mix on medium speed until the ingredients come together into a smooth ball, about 10 minutes. Cover and let stand for 15 minutes.
2. Preheat the Oven
Preheat the oven to 550°F (or as hot as your oven will go). If using a baking stone or steel, preheat it along with the oven.
3. Divide and Shape
Divide the dough into two equal portions (each about 168g). Gently shape each portion into a round. Cover with an inverted bowl to prevent drying out. Flour a work surface and rolling pin, then roll one piece of dough into a rectangle roughly 12" × 9".
4. Stretch the First Layer
Transfer the dough to the lightly oiled 16" × 12" Grandma pan. Gently stretch the dough toward the corners and edges of the pan, letting it overhang by about 1" on all sides. The dough should be paper-thin. Dot the stretched dough evenly with half of the mozzarella.
5. Add the Top Layer
On the floured work surface, roll the second piece of dough into a rectangle roughly 12" × 9". Lay it over the cheese. Pulling gently, stretch it so that it fully covers the cheese and extends about 1" past the rim on all sides. Run a rolling pin firmly along the pan's edge to trim the overhanging dough, then crimp or roll the edge to form a twisted rope border. Using your thumb and forefinger, pinch the top layer in several spots to tear open small, irregular holes; these allow steam from the melting cheese to escape.
6. Bake
Place the pan directly on the baking stone or steel (or on the lowest oven rack if you don't have one). Bake until the focaccia is deeply browned, blistered, and cracker-like on the top and bottom, 12 to 16 minutes.
7. Finish and Serve
Remove from the oven and let cool for 1 minute. Slide the focaccia off the pan onto a cutting board. Drizzle with a little olive oil, sprinkle with flaky sea salt, and cut into squares.
Storage
Leftover cooled focaccia can be wrapped well and refrigerated for up to 2 days. To reheat, place on a parchment-lined baking sheet in a 400°F oven for about 5 minutes, until warmed through and re-crisped.