I noticed cashews spike my T. Very strongly, and very clearly. I used to be allergic to them when I was a kid and recently started drinking almond/cashew milk (no hives or anything, so thought I was fine). After 10-15 times I realized there was a very clear 1 to 1 relationship between that and my T spiking.
It also happens when I drink certain types of beer (which also cause me GI issues). Unfortunately I have no idea which ingredient or which beers. In general though I'm realizing now there's a very clear link to my allergies and my T.