From start to finish, I fucked these up in every way imaginable.
1. The cookie dough. It calls for the butter, sugar, and flour to be blended in a food processor. I don't have one of those, so I figured I could use the Kitchenaid mixer. There was some dissent on twitter about whether or not that would actually work. Most people thought it would be OK, but that the cookies might just have a different texture. I tried it and two things happened: 1. flour flew throughout my entire kitchen at amazing speed and 2. the dough never formed. So I ended up having to mix it up by hand with a pastry cutter and that worked fine.
2. The caramel. I had never made caramel before so I was unaware of it's fragility. The first mistake I made was to double the recipe without increasing the size of the pan I was using. I dumped everything into a smallish saucepan which resulted in the butter not melting since it was floating in sticks at the top of the pan. To combat this, I turned up the heat to make the butter melt faster. Don't do this. The butter eventually melted but it never combined with the sugar and after 30 minutes of boiling and stirring, I had a thick, gritty, semi-burned sugar goo with an inch of oil floating on top. It could not be saved. So, at 10 PM I went back to the grocery store for more ingredients since I was now out of condensed milk and butter. I made the second batch of caramel in a bigger pan and melted everything together over super low heat, very slowly, stirring the whole time. This time the butter didn't separate, but it still took WAY longer than the 6-8 minutes the recipe says to thicken the caramel. It took about 25 minutes. Maybe it's because I doubled the recipe or maybe it's because of the very thick pan I was using, I don't know.
3. Starting these at 9:00 was a bad idea. After you pour the caramel on the cookie layer, you need to refrigerate it for 2 hours before you can pour the chocolate layer on top. Since I wasn't done making the caramel until 11:30, that was a lot of late night waiting. I actually only let it set for an hour because I just couldn't stay up any later, and then melted the chocolate and spread it on. I thought the hard part was over, but no:
4. The cutting. Because I was up so late making these, I let them chill in the fridge overnight (the recipe says to let it chill for 2 hours before cutting). You're supposed to cut them as soon as you take them out of the fridge so the caramel won't get all soft and oozy when you cut but I think because I refrigerated mine so long, I should have let them warm up a bit before cutting as the cold chocolate shattered everywhere. By the time I got to the end of the pan, it was warmed up enough that they were cutting without breaking, but I won't be winning any awards for presentation on these.
The good news: They taste AMAZING. If you're not a totally inept baker such as myself, you should totally make them.