Preheat the oven to 325 degrees F. Place a piece of parchment onto a rimmed baking sheet and spray with Primal Kitchen Avocado oil spray and set aside.
Separate the eggs (save the yolks for another recipe like my keto ice cream, hollandaise, mayo or lemon curd), and place the whites into a large bowl or stand mixer. Add the allulose, gelatin, salt and cream of tartar if using and whip the whites for a few minutes until VERY stiff.
Turn the mixer to low and gently mix the egg white protein powder into the whites. Do not over mix or it will end up like styrofoam.
Spread the protein sparing pretzel mixture onto the prepared baking sheet.
Bake for 8 minutes or until just starting to cook through. Remove from the oven and use a pizza cutter to cut into 1 inch thick strips. Gently use your hands to twist each strip into a pretzel shape and place back onto the baking sheet. Repeat with remaining strips of pretzel dough.
Place back into the oven and bake for another 10-15 minutes or until dark golden brown and cooked to your liking. Remove from oven.
If desired, brush the tops of each pretzel twist with melted butter and sprinkle with coarse salt. Serve with brown mustard if desired.
Store leftovers in the fridge for up to 4 days or in the freezer for up to a month.