Making a question with the verb "to go"

I don't think it's unique at all. That formulation is almost exactly the same as in French:

Tu vas voir le spectacle? Tu vas boire ce café?

It's just a form of the immediate future tense, which exists in a number of languages.

Going-to future is a complete article about what you asked for.

Summary:

"Usage"
Going-to future is a term used to describe an English sentence structure referring to the future, making use of the verb phrase to be going to.1 The verb "go" can also be used to indicate the future in some other languages.

"Origin"
The original construction involved physical movement with an intention, such as

I am going [outside] to harvest the crop.

The location later became unnecessary, and the expression was reinterpreted to represent a near future.

"Structure"
The going to future is formed as subject + be (in the proper form for the subject) + going to + verb + any other information.

Same structure in French, Spanish and Creoles.

Hope this helps.

I'm not sure it's exactly unique.

French has a similar construction:

Qu'est-ce que tu vas manger?

Same goes for Spanish:

¿Qué vas a comer?