Two comments about English "I am going to [do so-and-so]":

(1) In some cases, I would characterize it as simply a "marker" of the future tense: "I am going to make a sandwich for lunch = "I will make a sandwich for lunch" = Я приготовлю сэндвич на обед. (If you want to more clearly emphasize the meaning of "planning" or "intending", you can say "I think I'm going to make a sandwich for lunch" = "I'm planning to make a sandwich for lunch" = Я собираюсь готовить...)

Also consider the example "Try some of this 'baklazhannaya ikra' -- it may look strange, but I'll bet you're going to love the taste!!" Here, the sense of "planning/intending" (ты собирается любить эту икру) isn't even possible; "you're going to love it" can only be a simple future construction signifying "you will love it".

(2) In colloquial spoken English, "going to" in the sense of "собираться" or as a future-tense marker generally has a very different pronunciation than it does in contexts where literal motion is expressed. (As in "He was going to the library," Он шел в библиотеку.)

When there's no motion expressed, "going to" is usually "vowel reduced" to something like гойнгда, and sometimes contracted even further to ганна ("gonna"). And the first-person form "I'm going to" (because it's such a high-frequency usage) may be even more contracted/reduced, to something that sounds like амана, or even амо (this last pronunciation is stereotypically associated with African-American speech: "Ah-mo make a sammich" = "I'm going to make a sandwich").

But when "going to" signifies actual motion -- i.e., when it's translatable with a form of ходить/идти or ездить/ехать -- the pronunciation is more clear and careful:

"He's going to (гоинг ту) the kitchen because he's going to (гойнгда or ганна) make a sandwich." (Он идёт на кухню, потому что он собирается готовить сэндвич). Also notice that in the first clause, "to" is a directional preposition that governs the noun "kitchen", but in the second clause, it's an infinitive marker that really belongs to the verb "make", yet is phonetically assimilated with "going".