If you booked an excursion you'll be told to report to a designated area by a certain time. I can't tell you when or where that will be. Breakfast is always served, in both the Windjammer buffet and the main dining room. The dining room will be less hectic and can actually be a quicker choice on debarkation morning instead of fighting for a table at the buffet.
Ships don't have many candy choices. You really won't have much time to go hunting for easter bunnies that morning. Why not simply hide stuff at home before you leave for the cruise and have the easter basket thing when you get home?