Mix flour, yeast, salt, honey and water until a very wet dough forms.
Coat with 2 Tbsp olive oil and let rise 2½–3½ hours, until puffy and bubbly.
Grease a 9-inch cast iron pan with butter and olive oil.
Gently gather and fold the dough, then transfer to the pan.
Let rise another 1–2 hours.
Drizzle with the remaining 1 Tbsp olive oil, dimple, and finish with flaky salt + rosemary.
Bake at 450°F / 230°C for 25–30 minutes, until deeply golden and crisp underneath.
