I mean I should really just write two sentences for this post.
Find your oven.
Head that oven to 375 degrees.
Grab a dozen eggs.
Place an egg into each space of a muffin tin.
Put that tin in the oven for 30 minutes.
Most important step! When the eggs come out, plunge them into an ice bath immediately to stop the cooking process. Keep the eggs there until they're completely cooled.
Eat 'em, decorate 'em, whatever your heart desires.
(Seriously though, why did no one tell me about this sooner?)