Translation:Please give me a piece of chocolate cake.
It was always "Please give me a piece of cake or pie" at home, where I grew up in the southwest part of the US. We used the word "slice" to refer to a piece of pizza. Because the pizza parlor referred to selling pizza by the slice, so we used that word for pizza at home too. So it sounds strange to say a slice of cake or pie to me. Although I would know what that meant. It would be in someone else's home that was not from around where I was born, that would be for sure!