Combine the parsley, sage, mustard and shallot in a mini food processor and pulse until coarsely chopped and combined. Add the olive oil and blend to form a paste. Season with salt and pepper.
Season the pork loin with salt and rub the paste all over it. Lay the prosciutto slices on a piece of parchment paper, shingled in 2 overlapping rows to form a 12-inch square. Place the pork loin in the middle of the prosciutto square. Using the parchment to help you roll, roll the prosciutto up over the loin, pressing firmly to adhere the prosciutto to the loin. Continue to roll until the entire pork loin is tightly covered in prosciutto (the prosciutto should overlap itself). Refrigerate at least 1 hour, preferably overnight.
In a small saucepan, bring the sugar, maple syrup, BBQ sauce, star anise, cinnamon stick, orange zest and jalapeño to a simmer. Let cool to room temperature, or overnight in the fridge.
When you're ready to roast the pork, preheat the oven to 425 degrees F.
Place the butter, garlic and rosemary in a large, ovenproof saute pan and heat over medium-low heat until the butter is melted, about 2 minutes. Lay the prosciutto-wrapped loin in the pan seam-side down. Roast until an instant-read thermometer inserted in the center of the loin reads 120 degrees F, 30 to 40 minutes.
Brush the glaze on the loin and continue to roast to 135 degrees F for medium, 10 to 15 minutes more. Allow the meat to rest before slicing, then spoon the pan juices over the pork slices.