Make the filling: In a bowl, mix softened cream cheese, green onions, minced garlic, sugar, and (optional) salt until smooth and well combined.
Set up: Place wonton wrappers on your work surface and keep the stack covered with a damp towel so they don’t dry out. Set a small bowl of water nearby for sealing.
Fill: Place 1 wrapper with a corner facing you (diamond shape). Add about 1 teaspoon filling to the center.
Fold: Wet the edges lightly with water. Fold into a triangle, press out any air, and seal. Bring the two bottom corners together, dab with water, and pinch to seal into a classic wonton shape. Repeat, keeping assembled wontons covered.
Heat oil: In a deep pot or wok, heat 2–3 inches of oil to 350°F (175°C). Use a thermometer for best results.
Fry: Fry wontons in small batches (don’t crowd) for 2–3 minutes, turning as needed, until golden brown and crisp.
Drain and serve: Remove with a slotted spoon and drain on paper towels. Serve hot with sweet chili sauce, sweet-and-sour sauce, or a soy-vinegar dip.