1) Preheat the oven to 180 degrees C/Gas 4.
2)Put the molasses, tomato ketchup, mustard, and chilli in a blender and puree.
3) Scrape that into a big bowl, add the beans and season with salt and black pepper, and gently toss so that the beans are coated with the molasses mixture. Divide the mixture evenly amongst individual crocks.
4) Top each crock with a piece of pancetta, sprig of rosemary and a drizzle of extra-virgin olive oil.
5) Bake in the oven until the pancetta is browned and fat is rendered, about 25 minutes. Serve.