Chocolate caramel shortbread bars

These could also be called "super injurious shortbread bars" given I cut and burnt myself while making them.  How to avoid these things?  You know how your mom always yelled at you about lids of cans removed using can openers being sharp?  Well, they're actually sharp.  Take the lid off the can and throw it out.  Don't kid yourself into thinking you can empty out the can with the lid still half attached.  It will lead to blood.  Also, be careful while handling hot caramel.
So, these took way longer than I thought they would, probably in large part due to injury.  Also, I did not enjoy the 'make caramel in the microwave' method.  It felt like it took forever, everything was constantly separating, it bubbled over in the first bowl I used so I had to switch.  Bleh.  If I made these again, I'd probably just do it on the stove.
Also, I did milk chocolate instead of semi sweet because it sounded better.  And it came out delicious.
People loved these.  And then they heard how much butter was in them and they panicked.