Set the oven to 220°C / 430°F with the fan.
Place the cubed sweet potato on a baking pan and bake for 40 minutes.
Move the sweet potatoes to a bowl and mash with a fork until you get a unified puree. (You need to use 1.5 cups of puree for the recipe)
In a stand mixer bowl, place all the dough ingredients, except for the salt.
Knead the dough with the kneading hook for 2-3 minutes. Add the salt and continue kneading for 3-4 minutes more.
With your hand, create the shape of a ball from the dough and place in a greased bowl so it may rise.
Let the dough rise for an hour and a half or until it doubles in volume.
Set the oven to 180°C / 360°F with the fan.
Divide the dough into 2 balls.
Shape each ball to 5 equal strands.
For each strand, begin to braid.
Place the braided challah on a baking pan and brush with the beaten egg.
Sprinkle the sesame seeds.
Let the challah rise for 15 more minutes.
Bake for 25-30 minutes.
Cool at room temperature.
Enjoy!