On individual store anniversaries, Costco parties supersize with a massive sheet cake to match, and if you visit a store on its anniversary, you can score a slice on the house.

You will need a membership card to attend this party, but once you're in, you can expect a cake quite similar to the sheet cakes Costco regularly offers in its fan-favorite bakery.

Special store anniversary cakes understandably deviate from the standard size options, and bakers go all out to create cakes in the shape of the big box store itself.

However, Costco doesn't always announce these parties, so you'll have to be lucky enough to stumble upon the aisle and grab a slice should you visit a store on its anniversary.