3 1/4 cups bread flour
2 1/4 teaspoons instant or rapid-rise yeast
7 large eggs
1/2 cup water, room temperature
1/3 cup sugar
16 tablespoons unsalted butter
Vegetable cooking spray
Melt butter. Set aside to cool slightly.
Whisk flour, yeast, and salt together in large bowl.
Whisk 6 large eggs, water, and sugar together in medium bowl until sugar has dissolved.
Whisk in melted and slightly cooled butter until smooth.
Add egg mixture to flour mixture and stir with wooden spoon until uniform mass forms and no dry flour remains, about 1 minute.
Cover bowl with plastic wrap and let stand for 10 minutes.
Holding edge of dough with your fingertips, fold dough over itself by gently lifting and folding edge of dough toward middle.
Turn bowl 45 degrees; fold again.
Turn bowl and fold dough 6 more times (total of 8 folds).
Cover with plastic and let rise for 30 minutes. Repeat folding and rising every 30 minutes, 3 more times.
After fourth set of folds, cover bowl tightly with plastic and refrigerate for at least 16 hours or up to 48 hours.
Transfer dough to well-floured counter and divide into 4 pieces.
Working with 1 piece of dough at a time, pat dough into 4-inch disk.
Working 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.
(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.
Grease two 8½ by 4½-inch loaf pans.
After 5 minutes, flip each dough ball so seam side is facing up, pat into 4-inch disk, and repeat rounding step.
Place 2 rounds, seam side down, side by side into prepared pans and press gently into corners.
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.
Lightly beat 1 large egg with pinch salt.
Remove plastic and brush loaves gently with egg mixture.
Set loaf 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.