Heat oven to 375° and line a baking sheet with baking mat or parchment paper, then set aside.
In a microwave safe bowl combine almond flour, parmesan cheese, baking powder, baking soda, garlic powder, onion powder and sea salt. Whisk, then toss in grated mozzarella. Place butter on top, then microwave for 45 seconds. Mix with a wooden spoon, microwave for an additional 30 seconds, then mix again.
Crack the eggs into a small dish and whisk well. Remove 1 tbsp of the egg and set aside, then pour the remaining egg into the almond flour / cheese. Fold the eggs in gently using a wooden spoon until just combined, then gently fold in the vinegar. Do not over mix the dough or these keto hot dog buns could turn into breadsticks.
Divide the dough into four sections, then gently roll each section into a weiner sized log and place evenly on the baking sheet. Brush with the remaining egg wash.
Bake in the preheated oven for 12-14 minutes, until the tops are golden brown. Let sit for a few minutes to cool before slicing and filling with your hot dogs!