I got this recipe from a Scottish friend.
FINALLY GOT IT RIGHT!! after using at least 4 different recipes for these squares, this one is the only one that worked!! I did make sure I read all reviews first for this any other same type recipe. After reading I did a couple different things, I didn't have almond so used same amount of extra flour, poked holes in base before baking, came out fine. I did use non stick paper with non stick spray so it would come out of pan. I let the base get stone cold before adding caramel. I did boil caramel center for the full 7 minutes and yes I got the brown flecks in it, but you couldn't notice on the end product. Still not sure it would take I poured it on the base, let it sit in fridge for 30 mins or so then went directly to freezer until stone cold. The top I used half semi chips and half milk chocolate and added tbsp of crisco to make top shiny. As caramel was very cold, chocolate started to harden almost immediatly..which was great, b/c I then was able to score the chocolate at that time. Put it back in fridge, couple hours later, it removed from pan, cut along score lines, no broken chocolate, base was fine and didn't fall apart....yummy....I love these aquares and have finally found a recipe that works. - 10 Sep 2008 (Review from Allrecipes US | Canada)
I have made this recipe every year now for 3 years and each year I'm asked to share it. I've made one change - I substitute brown sugar (lightly packed) for the white sugar, which I feel gives it more of a caramel flavor. I haven't had any problems with the caramel setting up, but I do cook it for the full 7 minutes suggested. I use light corn syrup in place of the golden syrup. - 10 Jan 2005 (Review from Allrecipes US | Canada)
As is, the recipe is a 4-star, but I think it can be made into a 5-star. Other reviewers didn't mention having any trouble with an excess pool of butter forming after the caramel was cooked, but I sure did; I drained at least 1/4c of butter from the caramel before spreading it on my shortbread crust; otherwise, I would have had a mushy crust, and the gooey caramel that some complained of. I melted semi-sweet chocolate chips for the topping as I had no milk chocolate in the house; even though I'm a bigger fan of semi-sweet, I think milk chocolate may be better with this so it doesn't mask the flavor of the caramel so much; next time, I would definitely sub brown sugar for white in the caramel mixture to further bring out the flavor. Also, I had to cook the caramel mixture much longer than 5-7 minutes; it was more like 20-25 minutes to get it to the nice golden color I was looking for. This may have been because I had to use light corn syrup as it was all I had. This recipe does take some time; to speed things along, I put the shortbread in the freezer for 20-30 minutes to help with the cooling process, and again to help cool and firm up the caramel, and again to harden the chocolate top. Love the combo of shortbread, caramel, and chocolate; it is somewhat like a Twix bar! Thank you for sharing your recipe, Mary! - 26 Oct 2006 (Review from Allrecipes US | Canada)