Updated magic item to conform more closely to 3.5 rules and for fitting the Easter theme. How you introduce this to your campaign is up to the DM. I think it something that can be found or made or an item that an Easter Bunny may have. I don't think it is automatically found with the Easter Bunny as it has other eggs.
Due to the magical healing properties, this could easily unbalance a campaign. I would recommend that the PCs never get their mitts on the basket and only get a few eggs as a gift. Stealing an Easter Basket from the Easter Bunny is an EVIL act and should result in doom for the transgressor. Also, the basket is fragile and should easily take damage from improper handling.
The Basket of Never Ending Prismatic Eggs
Aura strong abjuration; CL 18th
Slot - (held) ; Price 270,000 gp; Weight 2 lbs.
In the hands of any humanoid, the woven wicker basket provides an unending supply of brightly colored eggs. Any creature eating one of these eggs gains a +1 morale bonus on all attack rolls and Will saves for 24 hours (not cumulative) and heals the eater 1d4 points of damage per egg eaten. The eggs are as nutritious and filling as normal chicken eggs but are filled with a delicious creamy white and yellow fondant. The basket holds 1 dozen eggs at a time.
In the hands of the Easter Bunny, the eggs can also be used as weapons if necessary. Each egg can be used as if it were a prismatic sphere, each color achieving a different effect.
For every egg used, a new egg appears in the following round. If the basket is emptied of eggs, it takes one minute to refill. The basket has a hardness of 4 and 8 hit points. Eggs removed from the basket are good for up to one month after which they begin to go bad. Anyone eating a bad egg is nauseated for one hour and gains no benefit from the egg.
Requirements Craft Wondrous Item, heroes' feast, prismatic sphere; Cost 135,000 gp, 10,800 xp
Note: I am really awful at statting up magical items. Updated for better usage.
Updated for pricing.