The Mignon Egg is the quintessential Finnish Easter egg, produced since 1896 by Fazer. As observed from the outside, a Mignon Egg looks almost exactly like one produced by a hen, bar a small mass of sugar on the bottom.
A Mignon Egg is indeed but a perfectly normal egg, drained of the yolk and the albumen, and filled with 54 grams (~2 oz) of - surprise surprise! - absolutely divine nougat/chocolate.
I have yet to meet a Finn not thoroughly obsessed with these sweet things.