1. Prepare the Pork Tenderloin

• Rinse the pork tenderloin under cold water and pat it dry with paper towels.
• Place the tenderloin into a large zip-top plastic bag.

2. Make the Marinade

• In a small bowl, whisk together the brown sugar, Dijon mustard, white vinegar, honey, maple syrup, chopped garlic, black pepper, and allspice until smooth.
• Reserve 5 tablespoons of the marinade for later use.

3. Marinate the Pork

• Pour the remaining marinade into the zip-top bag with the pork.
• Seal the bag, removing as much air as possible, and massage the marinade into the pork to coat it thoroughly.
• Refrigerate for at least 4 hours, but preferably overnight.

4. Prepare for Cooking

• Remove the marinated pork from the refrigerator 30 minutes before cooking to bring it to room temperature.
• Place the tenderloin on a wire rack over a baking sheet and let it rest uncovered. This will help dry the surface for better browning.

5. Sear the Pork

• Preheat your oven to 400°F (200°C).
• Heat 1–2 tablespoons of canola oil in a large oven-safe skillet (such as cast iron) over medium-high heat.
• Remove the pork from the marinade and let any excess drip off (discard the bag and marinade).
• Sear the pork on all sides, about 1–2 minutes per side, until it develops a golden-brown crust. This should take about 5 minutes in total.

6. Roast the Pork

• Transfer the skillet with the seared pork directly into the preheated oven.
• Roast for 15–20 minutes, or until the internal temperature of the pork reaches 145°F (63°C) when measured with a meat thermometer (the temperature will continue to rise as you let the meat rest).

7. Rest the Pork Uncovered

• Remove the skillet from the oven and transfer the pork to a cutting board.
• Let the pork rest uncovered for at least 10 minutes to maintain its crust and redistribute the juices.

8. Slice and Serve

• Slice the pork tenderloin across the grain into 1/2-inch thick pieces.
• Drizzle the reserved marinade over the slices for added flavor before serving.