You should watch the recent videos by “Nate from the Internet”, he keeps doubling the amount of vanilla extract put into cookies until you can detect a difference.
Spoiler: 1tsp, 2tsp, 4tsp, etc all taste exactly the same in the final product. After adding in cupfuls, the cookies start to taste bad from too much alcohol, but don’t taste any more vanilla than the 2tsp batch. He even tried with vanilla beans and whole pods.
Good point, and they did do zero. You can tell a difference between 0 and 1tsp. Some say 2tsp is “better” but most can’t detect it. Anything above 2 is the same.