Sweet Potato Tempura

1. Peel sweet potatoes and slice them into 1/4-inch thick rounds or sticks. Pat them very dry with paper towels. 2. In a large bowl, whisk together flour, cornstarch, baking powder, and salt. Gradually add the ice-cold sparkling water, mixing lightly with chopsticks or a fork until just combined. Do not overmix; lumps are desirable for crispiness. 3. Heat vegetable oil in a deep pot or wok to 350°F (175°C). 4. Dip each sweet potato slice into the batter, letting excess drip off. Gently place a few pieces into the hot oil. 5. Fry for 2-4 minutes per side, or until golden brown and crispy. Ensure the oil temperature remains consistent. 6. Remove tempura with a slotted spoon or spider and place on a wire rack lined with paper towels to drain excess oil. 7. Serve immediately with a sprinkle of salt or your preferred tempura dipping sauce.