I use this smooth raw cashew butter and it has no other ingredients but raw cashews.If you'd not using apple cider vinegar you can sub with another vinegar or lemon juice.
Lightly grease a silicone loaf pan (about 8 inches by 4 inches) or line the bottom of a pan with parchment paper and lightly grease the sides.
In a standing mixer (or a hand mixer) using the whisk attachment, add the egg whites to the bowl and beat them until stiff peaks form.
Transfer the egg whites to another bowl.
Add the cashew butter, egg yolks, vinegar, and apple juice to the standing mixer bowl and mix until well blended.
Fold the egg whites into the batter in the mixing bowl and blend with a spatula.
Add the coconut flour, baking soda, and salt to a clean bowl and blend with a whisk or fork.
Add the dry ingredient mixture to the batter and blend well with a spatula.
Pour the batter into the loaf pan and bake for 45 minutes or until the top it browned.
Remove the loaf from the pan and cool before slicing. Cover and store at room temperature for a few days, in the refrigerator for a week, or freeze for a few months.