01 - Toss calamari rings with buttermilk, salt, and black pepper. Cover and refrigerate for 15 minutes.
02 - Combine flour, cornmeal, paprika, garlic powder, and cayenne pepper in a shallow dish.
03 - Heat vegetable oil in a deep skillet or heavy-bottomed pot to 350°F.
04 - In a small saucepan, heat olive oil over medium heat. Add garlic and sauté for 30 seconds. Stir in crushed tomatoes, oregano, basil, sugar, salt, and pepper. Simmer uncovered for 10–12 minutes, stirring occasionally. Adjust seasoning as needed.
05 - Remove calamari from buttermilk, letting excess drip off. Dredge each piece in the flour mixture, coating thoroughly.
06 - Fry calamari in batches without overcrowding for 1½ to 2 minutes until golden and crispy. Remove with a slotted spoon and drain on paper towels.
07 - Serve crispy calamari immediately with warm marinara sauce, garnished with parsley and lemon wedges.