Of course here too I think "pumpkin spice" is about the spice that's used on pumpkins, and has little if any relationship to the pumpkin, especially as most pumpkin spice is probably applied to the horrible insipid go in a can that passes for pumpkin, but there is that fatal name. Poor pumpkin. There's probably as much pumpkin in pumpkin spice latte as there is lobster in a plate of lobster sauce.
Which is none, and is not designed to be. Pumpkin spice is a spice that's intended to be used with pumpkins, not intended to contain pumpkin; likewise, lobster sauce is a sauce intended to use with lobster, not to contain lobster. OK, I looked them both up on wikipedia.

And both can, of course, also be used for other purposes. As the main ingredient of pumpkin spice is cinnamon, I'm really not surprised that Starbucks serves pumpkin spice flavored lattes.
To react to dann, apparently pumpkin spice is also similar to Dutch "speculaaskruiden", a spice mix used in the
speculaas biscuit and
kruidnoten confectionery that are associated with our St. Nicholas feast. The
kruidnoten is the stuff that
Zwarte soot-black rainbow whatever Piet typically throws into the crowds.
You can cook up racist connotations for just about anything, if you cultivate the idea that it represents some kind of cultural privilege that is then considered racist by the commutative property of sloppy thought.
When I came into this thread, I didn't even know there are pumpkins that are white on the outside. I'm still a bit at a loss about the claimed racist connotations of pumpkins, but I may miss a lot of cultural background here. But dragging pumpkin spice as some sort of evidence into this seems far-fetched to me.