Why not?

Replacing 3D printing material with food, these are university students, they are very smart.

It says the layers of flavors in the article.

The article says it is actual food

No it will not, it is using mushed bananas and watery crackers.

This is a super slow method. 3d printing takes a long time.

It is made with natural ingredients? This requires more time than actually making a cheese cake. 3d printers are super slow. Also, where did you get the no natural ingredients part? The article says "Jonathan Blutinger and his team began by getting the seven ingredients ready for the print process. The Nutella, peanut butter, and strawberry jam needed no preparation. They were soft enough to pass through the syringe printhead. The bananas were also easy since they just had to be mashed. The graham crackers needed a little more work. They had to be crushed and mixed with water and butter to form a thick paste". These are all natural ingredients, and this will not solve world hunger