Adding layers to the block

Create a new object on the scene in 0,0,0 position

Rename gameObject to the same name of the block from the SquareTypes enum

Drag first layer block from the prefabs inward

Set first layer sprite on this object or keep it

Duplicate the object and set second layer texture

Add Layered Block component

Drab both objects to the apropriate layers of the LayeredObject

Drag it to the prefabs and delete from the scene