The question is if there's really a way to keep volatile aroma compounds from behaving like volatile aroma compounds. It's their stock in trade to evaporate quickly. This is not only why they disappear in the oven, but why they have such intensity of flavor and aroma in the first place.
If there IS a way to contain the aromatics—say, by extracting them into oil instead of alcohol, and solidifying the oil, is there any way this won't mute the flavor release? And what's worse ... having most of the aroma compounds vanish, or having them remain, but sequestered and muted?
As Chromedome suggests, we'd have to test it. And for something that's likely to be this subtle, I'd be skeptical of anything short of a blind triangle test with at least a few tasters.
You'd need to start on an even field—a good quality extract vs. a good quality powder. And you'd need to account for the biggest variable, which is concentration. There's no way to know what counts as an equivalent quantity of each, so ideally you'd make a few samples with each kind of vanilla, ranging from too little to too much.
