Crack an egg and beat it lightly until loose. Weigh out 38 grams of the egg and add it to the activated yeast. Refrigerate the leftover egg to be used as an egg wash later. Stir the yeast mixture to combine.

In a medium bowl, combine flour, salt, and 24 grams of sugar. Add the yeast mixture. Combine thoroughly with a wooden spoon.

Add the melted butter and mix until it is fully absorbed. Then form the dough into a ball. Cover with plastic wrap or damp towel and let sit for 20 minutes.

Lightly flour a dough scraper or your fingers if using. Scrape one side of the dough and fold it into the middle. Repeatedly scrape and fold the other sides in. Do about 10 folds in total. Then cover and let sit for another 20 minutes.

Scrape and fold the dough 10 more times. Then cover and rest it for 30 minutes.

Transfer out the dough onto a floured surface. Cut it into 3 equal pieces, then shape each into a ball. Let them sit on the surface for 15 minutes with a cover.

Using a rolling pin, flatten out each dough into an oval shape. Tightly roll it to the other side to form a log. Pinch the end seam to seal it tight.

Brush the top with the leftover egg from earlier. Using a scissor, cut along the center of the dough surface. Place strips of cold butter into the center. Sprinkle the top of butter with granulated sugar.

Bake in a preheated oven at 320°F (160°C) for 30 minutes or until golden brown on top. Remove from the oven and let cool completely on a wire rack.