Best practice for passing variables via recursive make

[Garrett Cooper]

Hi,
     Really simple question, but I was wondering what the best
practice was for passing variables (optionally with spaces) via
recursive make calls, i.e. is it:

$(MAKE) -C some_dir SOME_VAR=$(SOME_VALUE) all

$(MAKE) -C some_dir "SOME_VAR=$(SOME_VALUE)" all

     Out of habit I do the second option, but is it required? Is there
any "weirdness" associated with this? I'm asking because I got a weird
make related error where a value passed in via make replaced another
value, even though the top-level invocation appears correct.
-Garrett