01 - Place calamari rings in a bowl, cover with buttermilk, and season with salt and pepper. Refrigerate for 15 minutes to tenderize.
02 - Heat olive oil in a saucepan over medium heat. Sauté minced garlic until fragrant, about 30 seconds. Add crushed tomatoes, oregano, basil, red pepper flakes, salt, and pepper. Simmer for 10–12 minutes, stirring occasionally. Stir in sugar if desired. Keep warm.
03 - In a shallow bowl, combine flour, cornmeal, paprika, and garlic powder until evenly blended.
04 - Pour vegetable oil into a deep fryer or heavy pot. Heat to 350°F.
05 - Remove calamari from buttermilk, shaking off excess liquid. Coat rings thoroughly in the flour mixture, pressing gently to adhere.
06 - Fry calamari in batches without overcrowding the pot. Cook for 1–2 minutes until golden brown and crispy. Remove with a slotted spoon and drain on paper towels. Season lightly with salt immediately.
07 - Arrange crispy calamari on a serving platter with warm marinara sauce on the side. Garnish with lemon wedges and fresh chopped parsley.