01 - Heat the vegetable oil in a deep pan or fryer to 350°F (180°C).
02 - In a medium bowl, whisk together flour, cornstarch, baking powder, salt, black pepper, smoked paprika, and garlic powder.
03 - Gradually add cold sparkling water, whisking just until a smooth, thick batter forms without overmixing.
04 - Dip each spinach leaf into the batter, coating both sides thoroughly.
05 - Carefully place coated spinach leaves in hot oil, frying in batches to prevent overcrowding.
06 - Fry each batch for 1–2 minutes, turning once until crisp and golden brown.
07 - Remove spinach with a slotted spoon and drain on paper towels.
08 - Serve immediately, garnished with lemon wedges and flaky sea salt if desired.