You win some, you lose some - as with books, so with baking!
My biscuits are breaking, just like The Bridge of San Luis Rey, so instead of the plate piled high, which I'd hoped to be able to show you, I'm going for the minimalist look and a single biscuit to represent the batch:
Thornton Wilder's novel is set in Peru, so I used this recipe for alfajores, Peruvian biscuits sandwiched together with caramel. Points to note: rolling out the dough between two sheets of clingfilm as suggested is a good idea as it is very soft and difficult to work, even after chilling. Give them plenty of space to expand as they bake, watch your timing as they cook quickly, and handle them as carefully as you can because they break very easily. As to the manjarblanco, I used Bonne Maman Confiture de Caramel (and I forgot to dust them with icing sugar).
Despite mishaps and shortcuts, these are very good indeed - short (like the book they were made to go with!), melting, delicious.
