Combine the flour and yeast. Separately, add the water, egg yolks, oil, sugar, and salt into the bowl of the stand mixer. Then, add in the flour‑yeast mixture.
Mix with the dough hook attachment on low speed for 4 minutes and then on medium speed for 4 minutes. The dough should be slightly firm and smooth, but not sticky.
Proof the dough until doubled, about 1 hour.
Divide the dough into 6 separate 130‑gram pieces. Shape into oblongs and allow the dough to rest, covered, for about 10 to 15 minutes to let the gluten rest.
Fold the dough into thirds, then shape each third into a long rope about 24‑inches long.
Cut each rope into 3 smaller ropes, about 8‑inches long each. You should have a total of 18, 8‑inch ropes. Note: Make sure the ropes are all the same size, so your braid comes out evenly.
Dust the tops of the ropes lightly with bread flour.
Braid by pinching the tops of the ropes together and, beginning in the center of the strands, place the left strand over the center strand, then the right strand over the center strand. Repeat until you reach the end of the dough.
Pinch together the ends of the braids to seal.
Place the braided Challah on parchment lined sheet pans dusted lightly with bread flour.
Brush the completed braids with egg yolk wash.
Proof the dough, covered, until the dough springs back halfway, slowly to the touch, but does not collapse, about 1 hour.
Brush the dough again with the egg yolk wash before baking.
Select the Preheat function on the Cosori Air Fryer, adjust temperature to 300°F, and press Start/Pause.
Line the inner air fryer basket with parchment paper, being careful of hot surfaces.
Place the Challah braids into the preheated basket.
Set temperature to 300°F and time to 15 minutes, then press Start/Pause.
Remove when done and let cool completely on a wire rack.