Scotch toffee bars

I made a "full" recipe in my white square casserole dish. I think my written recipe is wrong; it called for 12 oz of chocolate chips (1 bag) but in reality you need 1 bag for a 9x13 pan and about half a bag for the roughly half-sized pan. I used a little more than half a bag because I hadn't quire realized that initially. One mistake: I ended up storing the bars in the fridge for a few days because my apartment was so hot, and then got them out of the fridge right before cutting them all up to take to a potluck. The chocolate was so brittle that it wanted to crack a lot, and the bars were very tough to cut in general. Best to cut at room temperature. As delicious as I remembered!