Preheat oven to 325 degrees F. Line a large baking sheet with parchment paper and grease with tallow spray (or avocado oil spray).
Place an oven safe cup filled with water into the oven.
Place the egg whites and apple cider vinegar into a stand mixer. Mix on high until stiff peaks form (about 4-5 minutes).
With the mixer on low speed, slowly add one at a time, egg white protein, gelatin, allulose and salt. Then add one yolk at a time.
Turn the mixer off and scrape the sides to combine everything well.
Grease a large ice cream scooper with tallow and scoop the batter to form buns and place on the prepared baking sheet. I use THIS one. Bake for 15 minutes. Turn the oven off and leave buns in the oven for another 15 minutes.
Remove from the oven and allow to cool before slicing the buns. Enjoy with a burger, pulled pork, egg sandwich, tuna salad... YUM!