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. Add minced garlic and sauté until fragrant, about 30 seconds. Stir in crushed tomatoes, oregano, basil, red pepper flakes, salt, and pepper. Simmer for 10–12 minutes, stirring occasionally. Add sugar if desired to balance acidity. Keep warm.
03 - In a shallow bowl, combine flour, cornmeal (if using), paprika, and garlic powder until evenly blended.
04 - Heat oil in a deep fryer or large pot to 350°F.
05 - Remove calamari from buttermilk, shaking off excess liquid. Dredge rings in the flour mixture, ensuring even coating on all sides.
06 - Fry calamari in batches without overcrowding for 1–2 minutes, until golden brown and crispy. Remove with a slotted spoon and drain on paper towels. Season lightly with salt immediately while hot.
07 - Arrange crispy calamari on a serving platter with warm marinara sauce on the side. Garnish with fresh lemon wedges and chopped parsley.