Combine flour and salt in a large bowl and mix well

Mix water, yeast, and extra virgin olive oil together

Pour the liquid mixture into the dry ingredients and mix until no dry spots remain; cover and rest for 1 hour

Perform the first round of stretch and folds by gently lifting and folding the dough around the bowl; cover and rest for 30 minutes

Perform the second round of stretch and folds; cover and rest for 30 minutes

Perform the third round of stretch and folds

Finish with coil folds by lifting the dough gently from the center and letting it fold under itself

Cover and place the dough in the fridge overnight for cold fermentation (or rest at room temperature for 30-40 minutes if short on time)

Remove dough from fridge and let it sit at room temperature for about 30 minutes to warm up

Butter a 23 × 34 × 3 cm tray and spread melted butter everywhere

Carefully transfer the dough into the tray and gently spread it with light hands

Cut butter into small cubes and place them over the dough; fold the dough from both sides and flip it over gently

Cover the tray and let it rest for 45 minutes to 1 hour for final proof

Preheat oven to 230°C (450°F)

Brush melted butter over the top of the dough

Using buttered fingers, press straight down into the dough across the surface to create dimples

Add water to the oven to create steam

Bake for 20-22 minutes until golden

Carefully remove focaccia from tray and brush with melted butter

Cool slightly before slicing and serving