Preheat the oven to 375 degrees Fahrenheit (190 degrees Celsius). Cover a sheet pan with Gefen Parchment Paper.

In the bowl of a stand mixer with the paddle attachment, combine one tablespoon of yeast, one cup lukewarm water and one teaspoon sugar. Let sit for about five minutes. Add honey, egg, oil and mix together. 

In a separate bowl, mix together Manhattan Blend, oats, baking powder and salt.

Add the dry flour mixture into the mixing bowl and mix on medium speed for three minutes. Gradually add another quarter cup of water and mix on medium speed until the dough is fully mixed. The dough should feel soft and slightly sticky, but not like a batter. Add more flour if the dough is too wet.

Turn the dough out onto a surface floured with Manhattan Blend or rice flour. Divide dough into three equally sized parts. Sprinkle flour on top of the dough to prevent it from sticking to your hands.

Carefully roll each portion into three long ropes. Add more flour to prevent the dough from sticking. Place each rope parallel to each other on the pan.

Pinch the top ends together and braid the dough into a plaited loaf. If the dough sticks to your hands, you can dip your fingers in oil to help stick the ends of the dough together. Let sit in a warm and moist area for 45–60 minutes covered with a warm wet towel to let the dough rise.

Egg wash the top of the risen challah with a lightly beaten egg and bake the the challah for approximately 30 minutes, or until the color is a golden brown and the outside is crispy.