This is an obscure a book that has an Easter theme or at least involved rabbits who produced these really ornate Easter eggs, in which some or at least one of them had another world inside. I seem to recall something about a Grand bunny or master rabbit or similar; but there also seemed to be some kind of theme where a child escapes their current world into one of the eggs (like a pied piper kind of story)
Stump the Bookseller
New format, same book stumper solving.
Have you ruled out. THE WORLD IN THE CANDY EGG by vin Tresselt, illustrated by Roger Duvoisin,1978.
The Country Bunny and the LIttle Gold Shoes
the country bunny is picked from all the other snobby bunnies to help deliver easter eggs, and at the end of the night, when she is tired out, the Kindly old bunny in charge gives her a special mission – to deliver a special egg to a sick child
The Country Bunny and the Little Golden Shoes for sure.