In a small bowl, mix brown sugar, cinnamon, garlic powder, cayenne, cumin, pepper and salt. Gently rub onto pork tenderloin.
In a large skillet, add olive oil and heat on medium-high heat until the oil is sizzling but not smoking.
Add pork loin, allowing to sear for 3-4 minutes before rotating. Sear each side, about 12 minutes total.
Transfer pork loin to roasting dish and place uncovered in oven for 15 minutes to finish cooking.
While it's in the oven, make the glaze.
Leave pork juices in skillet but adjust to medium-low heat.
Add chicken broth to the skillet, then stir, scraping up any bits of pork left in the pan. Allow to simmer for one minute.
Next, add the bourbon and brown sugar. Turn heat to medium-high and allow the sauce to reduce in the skillet for about 10 minutes, stirring occasionally. Add walnuts for the final 1-2 minutes of cooking.
Allow the pork loin to rest at room temperature for at least 5 minutes before slicing.
Serve cooked pork warm with bourbon glaze poured over the top.
Notes
A larger pork loin (over 1 lbs) may need a few extra minutes of roasting in the oven.