Preheat an oven to 450 degrees. In a mixing bowl, combine the almond flour, salt, baking powder, oregano, onion powder, melted butter, egg, mayo, and parmesan cheese. Mix with a spatula until you have a uniform, wet batter.
Fill 4 regular-sized muffin tins with batter, each one about ¾ full. Bake the biscuits for 12 minutes. Allow the biscuits to cool for a couple of minutes before removing from the pan. Let the biscuits cool fully before slicing in half to make the biscuit sandwiches.
Make 4 egg patties. For each one, crack a single egg into a coffee mug with a base that is the same size as your biscuit. Stir in a small pinch of pepper and whisk until the egg is half mixed. Microwave the egg for 30-40 seconds on high to cook through. The cooked egg should naturally release from the mug and you can slide it onto the base of a biscuit. Layer ¼ oz sliced cheddar on top of the hot egg so it melts. Repeat for all 4 sandwiches.
Cook the turkey bacon slices on your stovetop until crispy. Let the bacon cool for 1 minute before slicing them in half. Place the equivalent of 1 slice of bacon on top of each egg patty. Slice the avocado and arrange a little more than ¼ oz on to each sandwich. Place the top pieces of biscuit over the avocado slices and enjoy.