Welcome to WAGS, Jordan. While there's no absolute concrete proof, the general consensus is that this may have been made by Favorite Stove & Range or Chicago Hardware Foundry with Favorite patterns after Favorite went out of business. Wish I knew more, but I don't.
The C inside the diamond? Who knows what that signifies. Most of the regular skillets have size numbers inside the diamond. Again, I wish there were more info available.