Is there any chance you can keep him in his bed longer?
We got DS1 a day/night clock. He knows not to get out of bed until the sun's up on the clock - 7:30am.

If we really want a sleep in, we put cereal in a bowl and a small amount of milk in a bottle in the fridge. He is also 3 and is more than capable of pouring the milk in the bowl - you should give him a chance, he might surprise you.

You could also try a bit of tough love. He can come and say good morning, but then he has to go out and play until you're ready to get up. If he starts throwing a tantrum, pick him up and take him out of the room. If he comes back and keeps going, take him out again. He'll get the picture after a while.