Last week, a dear friend of mine sent me a blurry photo and recipe with this hilarious comment: “This recipe is my Christmas recipe nightmare! A favorite of my husband and youngest son but a living mess to make EVERY SINGLE YEAR. My son and my sister-in-law made it this year and this is the debacle. Burned on the edges, underdone in the middle, left the oven a smoking mess, and the dog had a go at it as well. This recipe is very old—handed down from Grandma Betty. It certainly could stand some updating!” She added: “And it’s too many cookie bars! No one can eat an 11 x 15 pan of raisin mumbles!!” (To which I replied, genuinely, “Oh, it’s supposed to be bars?!”) I’ve often said that I love to cook but I don’t really love to bake—baking typically requires precision, not my forte. But cookie bars seemed doable … and  the challenge enticed me. Here’s what happened. Skip to the finished and delicious recipe below! I started by cutting the recipe roughly in half—and …