Originally from Family Guy
, from the episode in which Mort Goldman said,"The kids were very mean to me in high-school. They used to call me tastycakes and shove pinecones in my ass."(As seen in Little Nicky)
Tastycakes is an adjective. It describes someone's ass. As if, it were tasty... As tasty as cake.
"Hey nigga, I came to your moms last night. I saw her tastycakes. It was awesome."
"I know nigga, I've seen them too.