Combine the flour, 2/3 ounce/19.1g water, 1/3 ounce/11g of the butter, the fleur de sel and the fresh yeast in a mixer with the paddle attachment. Mix for 10 minutes to develop gluten. Refrigerate for 15 minutes to chill the dough.
Roll the dough out into a square. Form the remaining butter into a package shape and place in the center of the dough. Fold over the corners of the dough to fully encase the butter. Roll out flat.
Fold the dough by folding the right side in and then the left side over the right (also known as a "letter fold" because the dough is folded into thirds). Roll the dough out and then make another "letter fold". Repeat the process, making and rolling out 2 more "letter folds", adding in the sugar in between. Roll the dough flat and cut into squares. Fold the corners of each square into the center. And fold those new corners into the center again. Push the dough into small ring molds.
This has to be done super-fast (and on a cool tabletop) or else the butter will start melting and the sugar will get watery.
Preheat the oven to 350 degrees F.
Place the dough in a warm place (i.e. above oven) until the dough is about double (or a bit smaller than double) in size, 15 to 20 minutes. Place the ring molds with the dough onto a silicone baking mat sprinkled with sugar. Bake for 25 minutes. Unmold immediately. Let cool.
Flour T45 is the purest white flour mainly used for pastries. It can be purchased online or at specialty baking supply stores. Sprinkling the silicone baking mat with sugar helps form a caramelized crust.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.