Chat GPT is and others are killing me. 2 questions:

What is this style of roof called?

Can it be built with engineered trusses but without doing a "bump out" and without having a taller wall under the raised section?

Gable end roof

Yeah yeah, but what about the higher part in the middle. No clue what that would be called.

Had an idea about how to build it, but would rather uses trusses.

I always just call it a pop up or bump up. I don't know if I've ever heard it called by any official name but I'll stay tuned for the architects.

Tell us WHY or what problem this solves? Higher ceiling room?

Gable on gable would describe it best, since it has no official USA term that I know.
In UK
https://positiveroofing.co.uk/blog/30-different-roof-types-and-styles-in-the-uk/
one might call it a baby/short Monitor
Neither helps labor/suppliers.

Roof trusses can be employed for all roofs depicted.

The "montor" SOP would be to raise those spring plates higher ceiling inside.

Mo' money option is a special truss with high heel.
https://osb.westfraser.com/blog/raising-the-roof-raised-heel-trusses/

Trying to add some aesthetic to keep a single story house from looking too "ranch style ".

Ai created a cool version and has this roof. I was surprised how much better it looked.

bump out the wall also and the roof when happen naturally

I thought of that, but im getting this house too big. Trying to avoid that.