I've just installed 3 peninsula base cabinets with doors on one side. The other side is thin material that I have glued 1/2" plywood in between the screw stringers using Fuze-It.
I have a thin, 4-4.5mm, matching panel, looks like compressed paper, that I need to adhere then this will have 3 door panels glued and tacked. The door I was thinking of using Fuze-It or a H.D. Construction tube adhesive. The panel I was thinking rolling on contact cement. Googling, some use 3M High Strength spray adhesive. I was going to use long strips of 3/4" plywood screwed through the back panel in to the plywood filler where the doors would go to help adhere the back panel. there's going to be one piece of corner moulding along the corner edge so I was going to tack it down there also.