Prepare a 9x13in cake pan by lining with parchment paper.
Prepare an ice cream scoop by coating with coconut oil and placing in the refrigerator until time to scoop out the batter.
Whisk together the honey and warm water in a small bowl and sprinkle the yeast over the top.
Set the yeast mixture aside in a warm place (100-105 degrees, ideally) to activate while preparing the other ingredients.
Add the egg white powder, cream of tartar, salt, gelatin, allulose and acacia fiber powder to the bowl of your stand mixer and whisk together.
Add the arrowroot powder the yeast mixture and whisk together.
Add the yeast mixture to the dry ingredients and whisk together lightly until moistened.
Start the mixer with the whisk attachment on low speed. Gradually increase the speed until full. Mix on full speed for 5-15 minutes until you get a very thick, glossy, marshmallow cream-like batter.
Reduce speed to low and add in the butter extract, if using, and frozen butter shreds.
Using your prepared ice cream scoop, portion the batter into the pan, making 12 rolls and sprinkle with flake salt, if desired.
Allow to proof in a warm spot (ideally 100-105 degrees) for 1 hour.
Meanwhile preheat the oven to 325 degrees.
After the 1 hour proofing time, bake the rolls in the preheated oven for 25 minutes.
I used and extra large #12 ice cream scoop (1/3 cup, 2 1/2 inch diameter) https://amzn.to/3SXdVVU (affiliate link - thanks!)