Preheat oven to 375ºF. Mist a 24-cup mini muffin pan with cooking spray. Gently mix cream cheese, crab and scallions in a medium bowl.
Place a wonton wrapper on a working space with 1 point facing you. Cover remaining wrappers with a damp paper towel and set a bowl of water nearby. Place 1 heaping teaspoon of cream cheese mixture in center of wrapper. Dip a finger in water and dampen edges on wonton wrapper; fold in half, forming a triangle. Press out air and pinch edges to seal. Place in a cup of mini muffin pan. (Edges will stick out.) Repeat with remaining wrappers and filling, setting extras aside. Mist wrappers in pan lightly with cooking spray.
Bake until browned, 10 to 15 minutes. Mist pan with cooking spray and repeat with remaining wontons. Serve with duck sauce, if desired.