English statements use a subject, maybe an auxiliary verb (or two or three or four auxiliary verbs) and a main verb.
"I would recommend ..." has "I" as its subject, "would" as its modal auxiliary verb and "recommend" as its main verb. The other parts of the sentence don't change this basic grammar.
In English questions, the subject and the (first) auxiliary verb (when there is one) change order.
"Would I recommend ...?" has the auxiliary verb "would" before the subject "I". The two possible questions are:
"Would I recommend to you to buy something?" (and my own answer to
that is, "Yes, I would" (this form is sometimes called a "yes/no question")
"What would I recommend to you to buy?" (and my own answers to that
are "A book", "A particular book" and "XYZ book from the market") (this
form is sometimes called a "wh- question" or an "information
In both cases, I am asking the question to myself, and not to you, maybe to check that I've correctly understood your request for a recommendation and maybe to give myself time to think. I don't have to ask you what I would recommend - I already know, and I'm about to tell you.
Your original sentence is a statement: "What I would recommend to you is to (do this)."