1 tablespoon very finely ground coffee beans (preferably French roast)
2 teaspoons packed light brown sugar
1 teaspoon chili powder
2 teaspoons kosher salt
2 tablespoons extra-virgin olive oil
2 1-pound pork tenderloins, trimmed
Combine the coffee, brown sugar, chili powder and salt in a small bowl. Add the olive oil and mix until combined. Divide the mixture evenly between the two pork tenderloins and rub to coat completely.
Prepare a charcoal grill for indirect cooking (medium-high heat if using gas). Place the tenderloins on the hot side of the grill, cover and cook, flipping once, until grill marks form on each side (about 4 minutes per side). Move to the cooler side of the grill and continue cooking an additional 7-9 minutes, or until the pork has reached an internal temperature between 140º and 145º.
Transfer to a cutting board and tent with foil. Allow to rest for 10 minutes before slicing and serving.