Prepare the Blossoms and Filling

1. Gently rinse the squash blossoms under cool running water and pat them completely dry with paper towels. Carefully open each blossom and remove the pistil from the center by pinching it at the base and pulling it out. Set the cleaned blossoms on a towel-lined tray.
2. In a small bowl, mix the goat cheese, chopped fresh herbs, garlic powder, salt, and pepper with a fork until smooth and well combined. The mixture should be soft enough to pipe or spoon easily.
3. Using a small spoon or piping bag, fill each blossom with about 1 tablespoon of the herbed goat cheese. Gently twist the tips of the petals together to seal the filling inside. The blossoms should feel plump but not bursting.

Make the Batter and Fry

1. Pour about 2 inches of vegetable oil into a deep skillet or Dutch oven and heat over medium heat until it reaches 350 degrees Fahrenheit. Use a thermometer to be precise — too cool and the blossoms absorb oil, too hot and the batter burns before the cheese melts.
2. While the oil heats, whisk the flour and ice-cold sparkling water together in a bowl until just combined. A few small lumps are fine — do not overmix. The batter should be thin and light, about the consistency of heavy cream.
3. Working in batches of 3 to 4, dip each stuffed blossom into the batter, letting the excess drip off, then carefully lower it into the hot oil. Fry for 2 to 3 minutes per side, turning once, until the coating is golden brown and audibly crackling. The blossoms will puff slightly and turn a gorgeous deep gold when ready.
4. Transfer to a plate lined with paper towels to drain. Sprinkle immediately with flaky sea salt while the oil is still glistening. Serve right away while they are hot, crispy, and the goat cheese inside is warm and melty.