Set your oven to 350°F and prepare a large baking sheet by lining it with aluminum foil.
Cook the breakfast sausages in a small pan over medium heat until fully done, then slice them into rounds and set aside.
With a serrated knife, carefully cut a deep V-shaped groove along the length of the baguette, stopping short of the bottom to leave half an inch as a base.
Remove the bread from inside the baguette gently, clearing out all crumbs to form a hollowed-out bread boat.
Brush the melted butter inside the hollowed-out baguette thoroughly using a pastry brush.
Place the buttered baguette on the foil-lined baking sheet and keep it ready.
In a mixing bowl, whisk together the eggs and milk until well blended.
Add the shredded cheddar, mozzarella, diced scallions, garlic powder, cayenne pepper, salt, and pepper to the egg mixture and stir to combine evenly.
Pour the seasoned egg mixture carefully into the hollowed baguette.
Arrange the sliced sausage rounds along the center of the egg-filled baguette.
Bake in the preheated oven for about 30 to 35 minutes or until the eggs have set completely.
Take the baked egg boat out of the oven and let it rest for 5 to 10 minutes before slicing and serving.
