01 - Place calamari rings in a bowl and cover completely with buttermilk. Let marinate for 15 minutes.
02 - Heat olive oil in a saucepan over medium heat. Add minced garlic and sauté for 30 seconds until fragrant.
03 - Stir in crushed tomatoes, oregano, chili flakes if using, sugar, salt, and pepper. Simmer uncovered for 10 to 12 minutes, stirring occasionally until slightly thickened. Stir in fresh basil and keep warm.
04 - In a shallow dish, mix together flour, cornmeal, garlic powder, paprika, salt, and black pepper until evenly combined.
05 - Heat vegetable oil in a deep pan or fryer to 350°F.
06 - Remove calamari from buttermilk, letting excess drip off. Dredge rings in the breading mixture, coating thoroughly.
07 - Fry calamari in batches for 1 to 2 minutes until golden brown and crispy, avoiding overcrowding. Drain on paper towels.
08 - Serve calamari hot alongside lemon wedges and marinara sauce for dipping.