Heat 1 tablespoon of vegetable oil in a skillet over medium-high heat. Add napa cabbage, bean sprouts, carrots, and mushrooms, stirring together. Cook 2-3 minutes until softened, then add green onions, cornstarch mixture, sugar, salt, and black pepper; stir and cook additional 1-2 minutes until thickened. Remove from heat and cool slightly.

Take a spring roll wrapper and lay it in a diamond shape. Brush the top corner with cornstarch mixture to seal. Place 3 tablespoons of filling in the center, fold the bottom over filling, tuck in sides and roll tightly to seal. Repeat with remaining filling.

Preheat air fryer to 400°F for about 3 minutes. Brush finished spring rolls with vegetable oil for crispiness.

Place spring rolls in a single layer in the air fryer basket. Cook for 12-15 minutes, flipping halfway for even crisping until golden brown.

Carefully remove from air fryer using tongs. Allow to cool slightly before serving with dipping sauces.