My friend Jen (www.jenscakes.com) and I made desserts for over 200 for a Christmas party. This was an exceptionally big hit. We used the large baking chips and raspberry filling available from cake supply. The large chips worked especially well because they had a better tendency to stay intact (rather than melt and disappear into bar). Double or quadruple recipe and bake in larger pan for bigger batch. We used jelly roll pans with 1" sides. Highly recommended! Adapted from a Pillsbury Bake-Off recipe.