it’s a piece of cake

a Determinative

— A is used when the following word could be any of a certain type. Compare "A book I saw on the shelf" and "The book I gave you yesterday".

a Noun

— A is the first letter of the alphabet. The letter "a" comes before "b". — In some schools, an A is a very high grade. Ron got an A on his earth science test.

piece Noun

— A piece is a part of something that can be or has been separated from it. The man cut a piece of meat and a piece of cake for dinner. I own a piece of land in the country. — A piece is one example of a class or set of things. He put a piece of wood on the fire. Can I have a piece of paper to write on? — A piece is something that is made by an artist. The piece of music was beautiful. I thought his earlier pieces were more creative than his more recent stuff. — In board games, a piece is an object that can be moved to mark your position. There are six types of chess pieces in the game of chess: the pawn, the knight, the bishop, the rook, the queen, and the king.

piece Verb

— If you piece something together, you use bring together enough information to understand something. They gathered enough information to piece together the family history. — If you piece something together, you put the pieces together. The scientists moved their shop to an empty parking lot to piece together all the bones.

of Preposition

— Made using. It is a house of cards.

cake Noun

— A cake is a sweet baked food. Natasha's mum baked her a cake for her birthday. Would you like some cake for dessert? — A cake is a food that is made into a flat, usually round, shape. At that time of year, we make small Japanese rice cakes called mochi. — A cake of soap or ice, is a hard piece of it. He took a cake of soap and started to wash. — If something is a piece of cake, it's very easy. Yesterday's test was a piece of cake. I got twenty out of twenty.

cake Verb

— If something is caked, then it is coated with a layer of some material. His shoes are caked with mud.