MAKES 2 LOAVES
Traditional loaves of brioche à tête achieve their fluted sides and conical shape from a brioche mold.
1. Transfer dough to well-floured counter and divide into 2 equal pieces. Remove golf ball–size piece of dough from each. Pat 2 large pieces of dough into 4-inch disks and 2 small pieces of dough into ½-inch disks. Working with 1 piece of dough at a time, work around circumference of dough; fold edges of dough toward center until ball forms. Flip dough over and, without applying pressure, move your hands in small circular motions to form dough into smooth, taut round. (Tackiness of dough against counter and circular motion should work dough into smooth, even ball, but if dough sticks to your hands, lightly dust top of dough with flour.) Repeat with remaining dough. Cover dough rounds loosely with plastic and let rest for 5 minutes.
2. Grease two 8- to 8½-inch fluted brioche pans. After 5 minutes, flip each dough ball so seam side is facing up, pat into 4-inch and ½-inch disks, and repeat rounding step. Place larger rounds, seam side down, into prepared pans and press gently into corners. Place smaller rounds, seam side down, in center of larger rounds, pushing down gently so only top halves of smaller rounds are showing. Cover loaves loosely with plastic and let rise at room temperature until almost doubled in size (dough should rise to about ½ inch below top edge of pan), 1½ to 2 hours. Thirty minutes before baking, adjust oven rack to middle position, place baking stone on rack, and heat oven to 350 degrees.
3. Remove plastic and brush loaves gently with remaining 1 egg beaten with salt. Set pans on stone and bake until golden brown and internal temperature registers 190 degrees, 35 to 45 minutes, rotating pans halfway through baking. Transfer pans to wire rack and let cool for 5 minutes. Remove loaves from pans, return to wire rack, and let cool completely before slicing and serving, about 2 hours.