Prepare the Filling: In a small bowl, whisk together the pumpkin puree, brown sugar, pumpkin pie spice, and Neufchatel cream cheese until the mixture is smooth and well combined.
Fill and Fold the Wontons: Lay the wonton wrappers on a clean surface. Brush the edges of each wrapper with the egg wash. Place about 1 teaspoon of the pumpkin mixture in the center of each wrapper. Fold the wrappers into triangles, pinching the edges tightly to seal.
Fry the Wontons: In a large, deep saucepan, heat about 1 1/2 inches of vegetable oil over medium heat until it reaches 320°F (use a deep-fry or candy thermometer to check the temperature). Fry 3-4 wontons at a time, cooking each side for 2-3 minutes or until golden brown.
Drain and Cool: Remove the wontons from the oil with a slotted spoon and transfer them to a paper towel-lined plate to drain and cool slightly. Repeat with the remaining wontons. Dust the fried wontons with powdered sugar.
Make the Maple Dip: In a small bowl, whisk together the powdered sugar, Neufchatel cream cheese, maple syrup, and ground cinnamon until smooth. Serve the dip alongside the warm pumpkin pie wontons for a delicious treat.