Preheat the oven to 350 degrees. Get out all the ingredients needed.
Sprinkle the pork loin with salt. Heat the butter and oil in a large ovenproof skillet over medium heat. Add the tenderloin and cook for 3 minutes per side or until brown.
Place the pork loin in the oven Bake for about 30 minutes. While Pork in baking Bring the pecans, maple syrup and coarse mustard to a boil in a saucepan, stirring frequently. Reduce heat and simmer for about 3 minutes or until thickened. Remove from the heat and stir in the vanilla. Carefully remove the meat from the oven and spread the maple, nut mixture on top of the the loin.
Return the pan to the oven and cook for an additional 20-30 minutes or until 160 degrees is reached on the thermometer.
Remove the tenderloin to a serving platter and cover loosely with foil. Let stand for 10 minutes to let all the juice reach all the portions of the meat. Slice the pork and serve with sauce remaining in the skillet and juices on the serving platter.