01 - Place calamari rings in a bowl and cover 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, dried 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, combine flour, cornmeal, garlic powder, paprika, salt, and black pepper.
05 - Heat vegetable oil in a deep pan or fryer to 350°F (180°C).
06 - Remove calamari from buttermilk, shaking off excess liquid, then dredge thoroughly in the flour mixture to coat evenly.
07 - Fry calamari in batches for 1 to 2 minutes until golden brown and crispy. Avoid overcrowding the pan. Transfer to paper towels to drain excess oil.
08 - Serve hot with lemon wedges and marinara sauce for dipping.