Preheat oven to 425ºF. Mist a baking sheet with cooking spray. Whisk cornstarch, 1 Tbsp. water, soy sauce and sugar.
Warm oil in a skillet over medium heat. Sauté coleslaw mix, water chestnuts, scallions and garlic until slaw has wilted, about 3 minutes. Stir in tofu; cook until hot and most of liquid has evaporated, about 3 minutes. Re-whisk cornstarch mixture and add to skillet. Cook, stirring, until thickened, 1 to 2 minutes. Remove from heat.
Lay 1 wrapper on a flat surface, a long edge facing you. Spoon 1/4 cup tofu mixture on bottom third. Fold sides in toward center; roll tightly away from you, enclosing filling. Place, seam side down, on baking sheet. Repeat with remaining wrappers and filling. Mist tops of egg rolls with cooking spray.
Bake until golden, 10 to 15 minutes. Serve immediately.
