Bring a large pot of salted water to a boil, then add your pasta and cook until just al dente, about 8-10 minutes. Reserve a cup of pasta water, then drain and set aside.
While the pasta cooks, peel and devein the shrimp if not already prepared. Mince the garlic finely and measure out chili flakes.
Heat the large skillet over medium-high heat and add the olive oil. Once shimmering, add the minced garlic and chili flakes. Sauté for about 30 seconds until fragrant and lightly golden, releasing a garlicky aroma.
Add the shrimp to the skillet. Cook for 2-3 minutes per side until they turn pink, opaque, and curl into a 'C' shape. Remove the shrimp from the skillet and set aside.
Pour the crushed San Marzano tomatoes into the skillet. Season with a pinch of salt and a small pinch of sugar if needed. Simmer over medium heat for about 10 minutes, stirring occasionally, until the sauce thickens slightly and develops a bright, smoky aroma.
Return the cooked shrimp to the skillet with the sauce. Toss gently to coat the shrimp evenly and cook for another 2 minutes until warmed through.
Add the cooked pasta directly into the skillet. Gently toss everything together to coat the noodles with the spicy sauce, adding a splash of reserved pasta water if the sauce seems too thick or sticky.
Finish with a taste and adjust seasoning if needed. Serve immediately, garnished with chopped herbs or a drizzle of olive oil if desired. Enjoy your fiery, flavorful shrimp arrabbiata!
