Preheat oven to 350°F. Place a small oven-safe bowl filled with about 1 cup of water in the oven to help create steam.
Add eggs, cottage cheese, cheddar cheese, kosher salt, and hot sauce to a tall bowl. Blend with an immersion blender until smooth.
Line a 7x10.5 inch baking dish with parchment paper and spray it with nonstick spray. Pour in the eggs and place in the oven.
Bake for 45 minutes, then remove and let cool slightly.
Cut the Hawaiian rolls in half horizontally. Place the baked eggs on the bottom half, then score to separate.
On one half, layer American cheese. On the other half, layer Gruyère, onion jam, and bacon.
Add the top half of the buns, press down gently, and cut into individual sandwiches.
Enjoy right away or wrap in foil and freeze for later. Check out the notes section below for my reheating instructions.