Preheat and prep. Heat your oven to 400°F (205°C).
Pat the pork tenderloins dry with paper towels. This helps with browning.
Season the pork. Sprinkle all sides with salt and pepper. Let it sit at room temperature for 10–15 minutes while you mix the glaze.
Make the glaze. In a small bowl, stir together apple butter, apple cider vinegar, maple syrup, smoked paprika, garlic powder, and cinnamon.
Taste and adjust salt, sweet, or tang as needed.
Sear the pork. Heat a large oven-safe skillet over medium-high. Add oil. Sear tenderloins on all sides until golden, about 2 minutes per side.
Don’t skip this; it adds flavor.
Glaze and roast. Turn off the heat. Brush the pork with half the glaze. Scatter thyme or rosemary and any apple/onion wedges in the pan if using.
Transfer skillet to the oven.
Roast to temp. Roast 12–18 minutes, depending on thickness, basting once with more glaze halfway through. Cook until the thickest part reaches 145°F (63°C) on an instant-read thermometer.
Rest the meat. Move the pork to a cutting board and tent loosely with foil. Rest 8–10 minutes so the juices redistribute.
Make a quick pan sauce. Place the skillet over medium heat.
Add broth and the remaining glaze. Scrape up browned bits and simmer 2–4 minutes until slightly thickened. Whisk in butter for gloss, and season to taste.
Slice and serve. Cut pork into 1/2-inch slices.
Spoon sauce over the top and serve with your favorite sides.