3 1/4 cups Bread Flour
3 1/4 cups All Purpose flour
1 Tbsp instant or active dry yeast
1 1/2 Tbsp salt
3 cups water, warmed
6 Tbsp unsalted butter, softened
1 egg with 1 Tbsp water
Whisk together flours, yeast, and salt in a large bowl. Add water and stir together with a wooden spoon to form a shaggy dough. It’ll take about 2-3 minutes to come together.
Cover the bowl with plastic wrap and let proof at room temperature for around 5-6 hours. The dough will double in size and may start to fall. This is OK. It just has to double initially. At this point the dough can be used immediately, or covered with plastic wrap and kept in the fridge for up to two weeks.
When you’re ready to bake, turn the dough out on a floured surface and lightly knead 3–4 times. The dough will be slightly sticky but resist from putting too much flour on it. A Bench Scraper works PERFECTLY here!
Cut the dough into 2 equal pieces. Shape each dough piece into a rectangle approximately 8×12″.
Place 1 1/2 tbl butter across the middle. Fold one third of the dough into the center, place 1 1/2 tbl butter on top of the fold followed by the other third. Place seam side-down in a buttered 9×5″ Bread Loaf Pan.
Cover with sprayed plastic wrap and let rise for approximately 1 hour, or until the dough has doubled in size. The dough will not rise above the pan; you just want it to double in the pan.
Preheat your oven to 450F with the rack in the middle.
In a bowl beat the egg and water until well combined. Using a pastry brush, brush the top of the bread with the egg wash. (See note if you do not want to use the egg).
Bake for 30–35 minutes, or until the top of the loaf has just begun to brown.
Remove from the oven and turn out on to cooling racks. Let cool for at least an hour before slicing.