Cut the salted butter into 6 pieces, 8g each, and place them on a tray lined with parchment paper. Refrigerate until ready to use.

In a large bowl, combine T65 flour and bread flour. Whisk to mix.

Add granulated sugar, instant yeast, and salt to the flour mixture. Whisk everything together.

Pour in the water and mix with a spatula, then with your hand, until a shaggy dough forms.

Knead the dough on a work surface for 7-8 minutes until it becomes smooth and can pass the windowpane test.

Add the unsalted butter to the dough and knead for another 2-3 minutes until it's fully incorporated.

Form the dough into a smooth ball.

Place the dough in a bowl, cover with plastic wrap, and let it rise for 90 minutes, or until it has doubled in size.

After the first proofing, gently deflate the dough and divide it into 6 equal pieces.

Roll each piece of dough into a teardrop shape. Cover them with plastic wrap and let them rest for 10 minutes.

Dust your work surface. Take one piece of rested dough and roll it out into a long, thin teardrop shape, about 18 cm long. Repeat for all pieces.

Cover the rolled dough and let it rest for another 5 minutes.

Using a rolling pin, roll out the dough into a very long strip, about 45 cm in length.

Place a piece of the refrigerated salted butter on the wide end of the dough strip.

Wrap the butter tightly, folding in the sides and sealing the edges to prevent leaks.

Lightly brush the surface of the dough with vegetable oil.

Press down the tip of the dough, then roll it up from the wide end towards the tip to form the bread shape.

Place the shaped bread on a baking sheet, seam side down. Lightly spray with water.

Cover the baking sheet with plastic wrap and let the bread rise for 60 minutes.

Preheat the oven to 220°C (428°F) using upper and lower heat.

After the final rise, remove the plastic wrap. Lightly spray with water again and sprinkle the tops with salt.

Bake in the preheated oven for 15 minutes, or until golden brown.

Once baked, transfer the bread to a wire rack to cool completely.