I hope you realize you have very few rights or protections at customs and immigration. A random check and your lack of declaration becomes a crime depending on how strict the customs agent wants to be, and they can be complete jerks (some are great though). No way to tell who you will get and if they want to turn your lie/omission into a criminal matter where you will find yourself detained until they feel like letting you go.

Why would it be incriminating yourself? You are bringing in perfectly legal goods. You can't incriminate yourself if you didn't commit a crime since they are legal items. Not declaring them is a crime.

You are required to declare everything you purchased outside the country - food or not. It is a lot more hassle to not declare it, get a random check, and many more problems. Just write down "Candy - $10, Cookies - $20" and they will probably just waive you through. Worst I ever had was a bag x-ray for stroopwafels from AMS - took about three minutes, and only that long because the guy in front of me had a suitcase full of cheese. Truthfully it was probably more about being a single male traveling alone from AMS (pot search) over the stroopwafels I declared.

Many years ago the husband of a coworker was a CBP agent. He told me declaring nothing was much more likely to trigger a secondary vs. declaring some souvenirs, candy, etc. My own experience confirms this as I got a puzzled look one time coming back from a week in Germany and declaring nothing. I got the "are you sure you didn't buy anything", and when my response was "I've been there three times in the last five weeks for work - I'm good.", he realized I was probably telling the truth and waived me on.