First, prepare the yeast by mixing the yeast with warm water and 1 teaspoon sugar and whisk until smooth. Let yeast stand until it puffs up, about 10 minutes.
Whisk in the 1 egg and 3 egg yolks, oil and remaining sugar and honey into yeast mixture until incorporated. Then add the flour a little at a time and salt and mix into a ball. Knead until smooth, about 10 minutes, adding more flour as needed (pun intended). You may not need all the flour.
Place the dough in a warm, cleaned bowl and cover with plastic wrap. Let the dough ferment until it has doubled in size, about two hours.
While challah is rising, make the latkes. Combine sour cream, cream cheese, flour, sugar and salt to make the sour cream filling. The cinnamon sugar apples I made right before using by tossing the peeled and diced apple in sugar and cinnamon.
Divide the dough into three pieces and roll out and flatten each. You want the dough as flat as possible. Fill each strand with one filled- latkes, sour cream and apples. Use as much filling as you can so you have lots of filling in the challah!
Seel up each strand, pinch the three strands at one end and carefully braid, making sure the closures are seeled well.
Line a baking sheet with parchment paper and place challah on the paper.
Cover and ferment another 45 minutes or so until it's light and fuffy looking (exact proofing timing for challah will depend on environmental conditions.)
Whisk the last egg yolk with 1/2 tablespoon water and generously brush over challah. Bake for 35 minutes at 350 degrees. Serve warm!