Hi Leslie! If Mickey Mouse is your character of choice, then it must be Chef Mickey's!
Chef Mickey's, located in Disney's Contemporary Resort, boasts a wonderful breakfast buffet, including Mickey waffles, and of course hosted by everyone's favorite mouse, Mickey Mouse! With his lady Minnie and pals, Pluto and Chip and Dale, Mickey makes the rounds at the tables, smiling and posing for pictures with all the CM guests. Spending his birthday morning by being able to meet and hug his favorite character will definitely be icing on the cake for him. Plus, the bonus is that the Contemporary Resort is steps away from the Magic Kingdom, so you won't have much travel time at all. You can hop on the monorail for the short ride, or take a nice stroll to the MK gates.
The breakfast buffet at CM is a hot ticket item so I would suggest that you make reservations early.
Don't forget to get your birthday pin at City Hall!
Hope this helps you plan your magical vacation!
-Malanie