In my personal opinion, the latter design (your requirement) is not a good one. It is not good user experience to scroll so much to look at content. Why is your business requesting it? What is the motivation?
I think the quickest way is to use a screenlayout of "content only". This way there is no formal header/footer. But you can add your version of a header/footer in your portal harness to scroll with the rest of the content.
I'm not sure if there is a quicker way or a way to re-use a header/footer layout and toggle the scroll behavior as a setting, which is what you are seeking. I was not able to find such an option yet.