Step 1

Whisk water and flour in bowl until no lumps remain.

Step 2

Microwave, whisking every 20 seconds, until mixture thickens to stiff, smooth, pudding-like consistency that forms a mound when dropped from the end of a whisk into the bowl, about 40 to 80 seconds.

Step 3

In the bowl of a stand mixer, whisk the flour paste from Step 1, egg and yolks, water, and oil until well combined.

Step 4

Add flour and yeast. Fit mixer with dough hook and mix on low speed until all flour is moistened, 3 to 4 minutes. Let stand for 20 minutes.

Step 5

Add the sugar and salt to the bowl and mix on medium speed for 9 minutes (dough will be quite firm and dry).

Step 6

Transfer dough to counter and lightly spray now-empty mixer bowl with vegetable oil spray. Knead the dough briefly to form a ball and return it to the oiled bowl. Lightly spray the dough with vegetable oil spray and cover the bowl with plastic wrap. Let dough rise until about doubled in volume, about 1 ½ hours.

Step 7

Line a rimmed baking sheet with parchment paper and nest in a second rimmed baking sheet to prevent the bottom of the bread from getting too browned or burnt.

Step 8

Transfer the dough to a clean counter and press into an 8-inch square, expelling as much air as possible.

Step 9

Cut the dough in half lengthwise to form 2 rectangles. Cut each rectangle in half lengthwise to form 4 equal strips of dough. Roll 1 strip of dough into a 16-inch rope. Continue rolling, tapering ends, until rope is 18 inches long. Repeat with remaining dough strips. Arrange ropes in plus-sign shape, with the end ends overlapping in the center by ½ inch. Firmly press the center of the plus sign in the center to seal the ropes to each other and to the counter.

Step 10

Lift the rope at 12 o’clock, bring over the center, and place in the 5 o’clock position. Lift the rope at 6 o’clock, bring over the center, and place in the 12 o’clock position. Lift the rope at 9 o’clock, bring over the center, and place in the 4 o’clock position. Life the rope at 3 o’clock and, working toward yourself, bring over the braid and place in the 8 o’clock position. Adjust ropes so they are at 12, 3, 6, and 9 o’clock positions.

Step 11

Repeat these steps, working toward yourself, until you can no longer braid. The loaf will naturally list to one side. Pinch the ends of the rope together and tuck both ends under the braid. Carefully transfer the braid to the prepared baking sheet. Cover loosely with plastic wrap and let rise until the dough does not spring back fully when gently pressed with your knuckle, about 3 hours.

Step 12

Thirty Minutes before baking, adjust oven rack to the middle position and preheat oven to 350 degrees F. Whisk together egg and salt. Brush the loaf with egg wash and sprinkle with sesame or poppy seeds, if using.

Step 13

Bake until the loaf is deep golden brown and registers at least 195 degrees F, 35 to 40 minutes. Let cool on baking sheet for 20 minutes. Transfer baked loaf to a wire rack and let cool completely before slicing, about 2 hours.