01 -
Preheat oven to 300°F (150°C). In a stand mixer or with an electric hand mixer, whip egg whites with vinegar on high speed until stiff peaks form, about 10-15 minutes. Set aside.
02 -
In a separate bowl, combine egg yolks, cottage cheese, baking powder, salt, whey protein powder, egg white protein powder, and allulose (if using). Whisk until well combined, or blend in a blender until smooth.
03 -
Gently fold the egg yolk mixture into the whipped egg whites, adding a little at a time to maintain airiness.
04 -
Pour mixture into a parchment-lined and greased 5×9-inch loaf pan. Bake on middle rack for 50 minutes, until a toothpick inserted in center comes out clean and top is golden brown.
05 -
When baking time is complete, turn off oven without opening door. Let bread remain in oven for additional 10 minutes. Then remove and allow to cool slightly.