Caramel crumb bars and recipes perfect for sharing

Every time I want to bake something for my coworkers I look for recipes that yield a lot – I want them to eat and have seconds if they feel like it (the sweet tooth in me finds that kind of thing important). :D
Therefore cakes, bars and brownies baked in a 13x9in pan are perfect – like these delicious caramel bars that so far have been the quickest baked goods to disappear at the office (