01 - Place the calamari rings in a bowl with buttermilk. Chill for at least 15 minutes to tenderize.
02 - Heat olive oil in a saucepan over medium heat. Add garlic and sauté for 30 seconds. Stir in crushed tomatoes, oregano, basil, sugar, salt, and pepper. Simmer gently for 10–15 minutes, stirring occasionally. Adjust seasoning to taste. Keep warm.
03 - In a shallow dish, mix flour, cornstarch, salt, pepper, and paprika until well combined.
04 - Heat oil in a deep fryer or large, heavy pan to 350°F.
05 - Remove calamari from buttermilk, letting excess drip off. Dredge rings in the flour mixture until well coated.
06 - Fry calamari in batches for 1–2 minutes, until golden and crisp. Do not overcrowd the pan.
07 - Transfer fried calamari to a paper towel-lined plate to drain. Serve immediately with warm marinara sauce, lemon wedges, and a sprinkle of parsley.