Quips & Anecdotes - Failed Peanut Brittle

I occasionally get in the mood to experiment with things food-related. The other day, I decided that I ought to try my hand at peanut brittle because I had all the ingredients available in the kitchen. I, unfortunately, terribly failed. For any of you out there who regularly makes candy, could you offer any help? I went with a basic recipe I found in a Food & Wine magazine from a while back - 1 cup white sugar, 1 cup water, 1 cup unsalted peanuts, 1/4 tsp cinnamon, and 1/2 tsp salt. I heated up the sugar and water together in a large pot (didn't have a saucepan handy) until it was boiling and then left that undisturbed. The instructions said that the sugar would eventually turn a light amber and that would be when I should take it off the heat. Though it was written to happen after about 12 minutes, my sugar boiled for more than 20 without any change in color. Impatient, I took it off the heat and mixed it in with everything quickly before pouring it onto a baking sheet.

I immediately saw that the concoction was not the amber/brown color that one ought to expect of peanut brittle. Nevertheless, I let it sit so it would harden. When I went to remove it from the baking sheet, I saw right away that the sugar had just crystallized and it would be difficult to take apart. It was. I definitely failed, and the peanut brittle ended up being very crumbly and too sweet. Anyone have any advice to give?