So I got some speed powder from USAmp, nice stuff but maybe just a hair too much moisture for my taste. I threw it in the oven for like 10 minutes at 300 and it came out with half the weight, and in yellow blobs kinda. Any way to recover this or did I fuck it up too much?
You had greasy speed of questionable purity.
Half the weight means you evaporated / vaporized a lot. Do a recrystallization from a solvent if choice, and take it from there.