Buttery Croissant Burgers on the Blackstone Griddle

Preheat your griddle to medium heat. I'm using my 36" griddle, if you are using something smaller you may have to do this in different batches.
In a small bowl combine salt, onion powder, garlic powder, paprika, and pepper. Mix to combine and set aside.
Shape your ground beef into 4 oval patties, about the same shape and size of your croissants.
Add a little oil to a portion of your griddle and add the onions. Cook until they have started to get a little bit of color to them, then remove from the griddle.
While the onions are cooking, add your burger patties to the middle section of your griddle. I like to slightly press them down with a burger press, but not completely smash them. Season the patties with half of the seasoning then allow to cook for 3-4 minutes before flipping. Season with remaining seasoning, top with the sliced cheese and cook for an additional 3-4 minutes.
While the burgers are cooking, cut the croissants in half and cover in shredded cheese before placing cheese side down onto the griddle. Cook for about 2 minutes until the cheese gets melty and slightly crispy before removing from the griddle.
Assemble your burger by adding the burger patty to the bottom croissant bun, then sauce, grilled onions, and top croissant. Finish of with melted garlic butter if desired.