Directions

1. Preheat the oven to 350 degrees. Turn it off after it reaches temperature, so that when it's time for the dough to rise, the oven will be warm, but not hot.
2. Lightly flour (or line with parchment paper) a baking sheet and set it aside.
3. In a large mixing bowl, whisk the yeast and the pinch of sugar into 1/2 cup warm water, and let sit to activate, 3-4 minutes (it will become foamy). 
4. In a separate bowl, whisk together the remaining sugar, the oil, the pumpkin, 2 of the eggs, the nutmeg and the salt. Continue whisking until completely incorporated. 
5. Gently fold the pumpkin-egg mixture into the yeast-water mixture.
6. Add the salt.
7. Add the flour gradually, stirring as you go. Eventually, you should have a soft, rich dough.
8. Flour a smooth, clean surface (like a countertop or large cutting board) and turn the dough out onto it. 
9. Knead the dough for 7-8 minutes, until smooth and elastic. Form it into a large ball.
10. Clean the dough debris out of the bowl you mixed it in, and pour about 2 tbsp olive oil into it. 
11. Place the dough into the oiled bowl and roll it around to make sure it is completely covered with oil.
12. Cover the bowl with a clean dish towel and place in the warm (but not hot) oven.
13. Let rise for 1 hour, or until roughly doubled in size.
14. Punch down the risen dough, then pull it into a smooth ball.
15. Place it on a flat, lightly floured surface.                                                            
16. Use a sharp knife to divide the dough into 3 equal-sized pieces.                              
17. Roll the dough pieces out on the floured surface into thick snakes, about 14" long.        
18. Place the right-most dough snake over the center dough snake.                                
19. Place the left-most dough snake over the new center (former rightmost) dough snake.
20. Continue this pattern, until the dough is almost entirely braided.                             
21. Turn the braid around and continue the pattern with the unbraided ends.                    
22. Transfer the challah to the prepared baking sheet.
23. Whisk together the remaining egg and 3 tablespoons of water. 
24. Paint the dough with one coat of egg wash.
25. Let rise for 30 minutes, until nearly doubled in size.                  
26. Once it has risen, paint the challah with more of the egg wash.
27. Preheat the oven to 350 degrees F.
28. Bake the challah for 30-35 minutes, or until golden-brown, and hollow-sounding when rapped gently on its bottom.
29. Let cool slightly, then serve.