In a large bowl, combine the flour, garlic powder, paprika, salt, black pepper, and cayenne pepper. Mix well.

Pour the buttermilk into another bowl.

Dip each calamari ring into the buttermilk, allowing excess to drip off, then coat it in the flour mixture. Shake off any excess flour.

In a deep skillet or pot, heat about 2 inches of vegetable oil over medium-high heat until it reaches 350°F.

Carefully add the coated calamari rings to the hot oil in batches, frying for about 2-3 minutes or until golden brown and crispy. Avoid overcrowding the pan.

Using a slotted spoon, remove the fried calamari and place them on a paper towel-lined plate to drain excess oil.

Serve immediately with lemon wedges and marinara sauce for dipping.