Bring 4 quarts water to rolling boil, covered, in large Dutch oven or stockpot.

While water is heating, heat 12-inch heavy-bottomed skillet over high heat for 4 minutes. Meanwhile, toss shrimp, half of red pepper flakes, 2 tablespoons olive oil, and 3/4 teaspoon salt in medium bowl. Add shrimp to skillet and quickly spread in single layer; cook, without stirring, until bottoms of shrimp turn spotty brown, about 30 seconds.

Off heat, stir to turn shrimp, and add cognac/brandy; let stand off heat until cognac warms slightly, about 5 seconds, and return pan to high heat. Wave lit match over skillet until cognac ignites; shake skillet until flames subside, transfer shrimp to medium bowl, and set aside. *I had a lot of trouble with this part, mostly because I think my pan was too hot. Never got the brandy to light, but the shrimp were still delicious! If the brandy won't light, keep on eye on the shrimp and cook them as directed, no more.

Off heat, cool now-empty skillet 2 minutes; return to burner and reduce heat to low. Add 3 tablespoons olive oil and 3 tablespoons garlic; cook, stirring constantly, until garlic foams and is sticky and straw-colored, 7 to 10 minutes.

Add remaining red pepper flakes, 3/4 teaspoon salt, sugar, tomatoes, and wine; increase heat to medium-high, and simmer until thickened and fragrant, about 8 minutes. Stir in reserved shrimp and accumulated juices, remaining 1 tablespoon garlic, and parsley and simmer until shrimp have heated through, about 1 minute longer. Off heat, stir in remaining 1 tablespoon olive oil. *I think I was thrown off by the flambe-ing and forgot to drain my canned tomatoes. This made for a very thin sauce, which I just reduced for longer than 8 minutes. Still turned out great!

While sauce simmers, add linguine or spaghetti and remaining 1 tablespoon salt to boiling water, stir to separate pasta, cover, and cook until al dente; reserve 1/3 cup pasta cooking water and drain pasta. Transfer drained pasta back to now-empty Dutch oven or stockpot; add about 1/2 cup sauce (without shrimp) and 2 to 3 tablespoons reserved pasta cooking water; toss to coat. Divide pasta among warm serving bowls, top with a portion of sauce and shrimp, and serve immediately.