1: Lightly grease a large bowl or proofing tub with extra-virgin olive oil.
2: In the bowl of a stand mixer, add the warm water.
Add the softened butter (it’s important the butter is soft to ensure it mixes well) and mix with a wooden spoon. The butter won’t dissolve, but it should be very soft.
3: Add the flour, yeast, sugar, and salt.
Mix on a low speed for 5 to 10 minutes until the dough is silky and slightly elastic. With wet hands, lift the dough and shape into a smooth ball before transferring it to your oiled bowl or proving tub. Cover with plastic wrap or an airtight lid. Proof for 2 hours, or until it doubles in size.
4: Grease the flat pan with butter, then scatter a thin layer of fine semolina flour over the top.
Remove the packaging on the Camembert and place it in the center of the pan. Cut a few deep slices across the center of the cheese, then insert small sprigs of rosemary.
5: On a lightly floured surface, use a scale to divide and weigh the dough into 3 equal pieces.
Stretch each piece out into narrow strips roughly 24 inches (60 centimeters) long. Lay the pieces side by side and begin plaiting the dough: Cross the right strand over the middle strand, then cross the left strand over the now-middle strand. Continue the braid, alternating right and left strands.
6: Once the plait is finished, curl it around the Camembert on the tray.
(If you have excess dough, cut the overlapping section and bake it on its own as a snack.) Pinch the ends together to form a closed wreath around the cheese.
7: In a small bowl, mix the egg and a teaspoon of water to make an egg wash.
8: Brush the dough with the egg wash, then sprinkle sesame seeds over the surface.
9: Cover the dough with a large bowl or deep tray, or place inside a plastic bag with the end folded over to keep any air out.
Let the dough proof for 30 minutes.
10: Fire up your oven, aiming for 625° F (330° C) on the baking stone inside.
Aim the thermometer at the center of the stone to quickly and accurately check the temperature.
11: Place the tray in the oven and turn off the gas, or, if using wood or charcoal, close the baffle to dampen the flames.
12: Cook for 9 minutes in the residual heat, rotating the pan 180 degrees halfway through.
13: If cooking with gas, return the oven to its lowest setting.
If cooking with wood or charcoal, open the baffle, but maintain a low flame, using a charcoal bed if possible. Cook for 9 more minutes, making sure to turn the pan every 2 to 3 minutes. The dough should puff up, start to smell delicious, and turn a deep golden brown.
14: Remove the tray and spoon cranberry sauce onto the melted cheese.
Serve right away.
