"As easy as pie is a popular colloquial idiom which is used to describe a task or experience as pleasurable and simple. The idiom does not refer to the making of a pie*, but rather to the act of consuming a pie ("as easy as eating a pie"). The phrase is often interchanged with piece of cake, which shares the same connotation."
In this case, though, making the pie is almost as simple (and pleasurable) as eating it. Now I clearly have to figure out how to make a Piece of Cake Cake.