Lightly coat a 12-cup muffin tin with cooking spray.
Using an electric mixer, beat all filling ingredients together until they thoroughly combined.
Place a wonton wrapper in the bottom of each muffin cup. The corners should stick up.
Lightly coat the wonton wrappers with cooking spray.
Layer a second wonton wrapper in each muffin cup so that all four corners of both wonton wrappers are pointing up. You should see eight corners around each muffin cup.
Evenly divide the pumpkin mixture in the muffin cups. Gently tap the muffin tin on your counter a few times to level the filling in the cups.
Sprinkle pecans over the top of each muffin cup.
Place the tartlets in the oven and bake 15-20 minutes, checking every 3 or so minutes. If the wonton corners start to burn, you can loosely cover with foil. The wontons should be crisp and browned when done.
Remove the muffin tin from the oven and let cool in the pan for 3-5 minutes.
Using a large spoon, or your utensil of choice, gently remove each tartlet from the muffin tin and place on a cooling rack. Once room temperature, refrigerate until ready to serve.