Preheat oven to 350 degrees. For pork tenderloin sear:

Stir together salt, pepper, cumin, chili powder, and cinnamon, then coat tenderloins with spice rub.

Heat oil in an ovenproof 12-inch heavy skillet over moderately high heat until just beginning to smoke, then brown pork, turning, about 4 minutes total. Leave pork in skillet.

For brown sugar glaze roast:

Stir together brown sugar, garlic, both juices and Tabasco (if desired). You want this mixture to be spreadable, so add more brown sugar if too much liquid; add more juices if not quite spreadable.

Spread onto top of each tenderloin, turning each to surround tenderloin with glaze. Once around, spoon remaining glaze atop each tenderloin.

Roast in middle of oven until thermometer inserted diagonally in center of each tenderloin registers 145°F, about 25- 30 minutes.

Let pork stand in skillet at room temperature 10 minutes. (Temperature will rise to about 160°F while standing.).