Preheat oven at 325 degrees F and line a 9 by 13 baking sheet pan with parchment paper or silpat or grease.
Place your egg whites in a stand mixer with vinegar and whip until stiff peaks. This should take about 10-15 minutes. Set aside.
Place the egg yolks in a blender with wet ingredients (sour cream) and then remaining dry ingredients and blend until incorporated and a smooth batter forms.
With the stand mixer on low speed, slowly pour in the egg yolk mixture until it's all incorporated.
Pour this pancake batter into your 9 by 13 prepared pan.
Bake on the middle shelf of preheated oven for 25-30 minutes or until a toothpick or skewer stick in the center comes out clean.
Store in an airtight container in the fridge for up to 5 days or freeze for up to 3 months. Reheat by removing one or two from the freezer and microwaving for 30 seconds to 1 minute.