01 - Slice cleaned squid into 0.4-inch rings; halve any large tentacles.
02 - Toss squid with salt, black pepper, and lemon juice in a bowl. Set aside for 10 minutes.
03 - Whisk together flour, cornstarch, baking powder, and cayenne pepper in a medium bowl.
04 - Gradually whisk in cold sparkling water until batter is smooth but slightly thick.
05 - Heat vegetable oil in a deep fryer or deep pan to 350°F (180°C).
06 - Pat squid dry with paper towels. Dip each piece into batter, letting excess drip off.
07 - Fry squid in batches for 2 to 3 minutes until golden and crispy.
08 - Remove fried squid with slotted spoon and drain on kitchen paper. Serve immediately with lemon wedges and parsley.