Tuck the thin, tapered end of the tenderloin under the roast, then tie the entire roast every 1 1/2 inches.
Combine 1 tablespoon salt, 1 tablespoon pepper, and sugar in small bowl and rub all over tenderloin. Transfer tenderloin to wire rack set on rimmed baking sheet and let stand at room temperature for 2 hours.
Bread Crumb Topping: Pulse bread in food processor to fine crumbs. Transfer bread crumbs to medium bowl and toss in 2 tablespoons parsley, 2 teaspoons thyme, 1/2 cup parmesan, and 2 tablespoons oil until evenly combined.
Herb Paste: Wipe out food processor and process remaining 6 tablespoons parsley, 2 tablespoons thyme, 3/4 cups cheese, 4 tablespoons oil, and garlic until smooth paste forms. Transfer herb paste to small bowl.
Adjust oven rack to upper-middle position and heat oven to 400°F Roast tenderloin 20 minutes and remove from oven. Using scissors, cut and remove twine.
Using a spatula, spread the herb paste evenly over the top and sides of the tenderloin.
Press the bread-crumb mixture evenly onto the roast, using the other hand to catch the crumbs and keep them from falling through the rack.
Roast until thickest part of meat registers about 130°F and topping is golden brown, 20-25 minutes. (If topping browns before meat reaches preferred internal temperature, lightly cover with foil for balance of roasting time and remove while roast rests.).
Let roast rest, uncovered, for 30 minutes on wire rack. Transfer to cutting board and carve. Serve.