The second time around, I adjusted my method, fully dissolving the sugar first over medium-low heat. Then I boiled the sauce gently, occasionally swirling the mixture. But the mixture took longer than expected to turn caramel in color, and, after about 10 minutes of boiling, it too turned into a crystallized mess.
After two tries, I feel more determined than ever to figure this out. Do you have any ideas what might've gone wrong? Should I have cooked through the crystallization stage? Was the heat too high?