Early Riser Schedule

Hi all! I’m looking for advice/tips for my 15 month old who is an early riser (5:45). He typically wakes up so cranky and miserable in the morning. He screams and whines and rubs his eyes essentially until I put him down for a nap which he could really hold out only until 9:30 at the latest. The problem with this is he only naps for an hour, and then he is up for the rest of the day which is a huge stretch as well. He won’t take a second nap no matter how hard I try. Is anyone else in the same boat/do you have any advice?