Ask Lemmygrad

I promise I'm not a wrecker, I just have trouble finding Marxist sources for these things that aren't big books on top of what I'm already reading. I think I understand that it says the exchange value of a product is proportionate to the labor time used to create it. Am I getting that correct? More labor-intensive commodities, or products requiring more specialized tools to make would cost more. And I know I've heard the criticism before. Heard it pretty much all my life. "Is a cookie still worth its labor if it's burnt? Is a pie worth the labor if it's a shit pie?" I have heard people say that Marx addresses such criticisms in Capital, but I haven't gotten around to those tomes yet. Could someone explain to me how they are addressed and maybe straighten out other things I may have gotten wrong?