In a large mixing bowl, add in 1/4 cup warm water, the yeast, and 1 tsp of sugar. Let sit for 10 minutes to activate. After 10 minutes the yeast mixture will be foamy/bubbly. If you don't see this, your yeast may be inactive or your water may be too hot, and you'll need to do this step again.
Add in the remaining warm water and sugar, half of the beaten egg (yes half, save the other half), egg yolks, honey, oil, salt, and spices and whisk to combine. Add in the brown sugar and pumpkin and whisk.
Begin adding in the flour a bit at a time, and knead in to form a dough. Move the dough to a floured surface (set your bowl aside, you will need it in the next step), and continue kneading and adding flour until the dough is just a bit tacky, and when you poke the dough it immediately springs back--approximately 10 minutes.
Preheat the oven to 200 degrees. Once the oven reaches 200 degrees, turn it off. Thoroughly spray the large mixing bowl with cooking spray, and move the dough into the bowl. Cover with the bowl with plastic wrap and place the bowl on top of the warm oven. Let the dough rise for 1 hour.
Remove the plastic wrap from the bowl, punch down the dough to remove the air bubbles. Re-cover the bowl with plastic wrap, place the bowl inside the oven (leave the oven off), and let rise for 1 more hour.
Assembly & Baking
Preheat the oven to 350 degrees. Line a baking sheet with parchment paper and set aside. Lightly flour a surface (mat or counter) and transfer the dough to it. Divide the dough into three, four, or six equal parts (depending on what kind of braid you'd like to do). We'll walk through six strand braid. Take each portion of dough and roll it into a snake. I like to do this with two hands together, spreading my fingers out as I go so the snake is uniform thickness throughout (picture typing on a computer, rolling outwards).
I recommend watching the video reference for a quick guide. Take the six strands and lay them out vertically on the mat. Pinch the tops together and fan out the bottoms--the overall shape will now resemble a pyramid. We're always going to start on the right hand side. Take the strand all the way on the right and weave it to the left, over 2 strands, under 1 strand, over 2 strands, settling now all the way on the left. Take the new strand all the way on the right and repeat this process until the whole loaf is braided. Pinch the loose ends together and tuck them under the loaf. Place the braided loaf on the prepared baking sheet.
Take the reserved egg and mix it with 1 tsp of water. Use a brush to gently egg wash the challah, making sure to get the nooks and crannies. Allow the loaf to rest for 10 minutes. Bake for 20 minutes, rotate your pan and bake for 15 - 20 more minutes. If the challah is golden brown and you think it's done, use a potholder to flip the bread over and lightly tap on the bottom of the loaf. If it sounds hollow, your challah is done. For a little added shine and richness, brush the warm loaf with melted butter. Transfer the challah to a wire rack to cool completely prior to slicing.
Enjoy this Pumpkin Challah on its own, with some good butter, or really go for the gold and turn this into the greatest french toast of all time!