If your cake pans are 9x1 1/2 rather than 9x2, you can use them anyway, but leave behind about 1/3 cup of the batter so that the cake won't rise over the top.
The frosting came together nicely. I used a thick, nonstick, black saucepan rather than a metal pan, so the sugar took a little longer to melt, but the candy came to 235 at a nice, even pace. The most difficult part of the recipe was knowing just when to pour the caramel onto the cake. It needed to be soft enough to spread out, but cool enough to set.