Make the filling: Stir the bananas, sugar, cinnamon, and coconut together in a small bowl, lightly mashing the bananas as you mix. The mixture should still be a little chunky.
Make the sauce: In a small sauce pan, bring the milk and coconut milk to a boil then remove from the heat.
Beat the egg yolks and sugar together in a medium bowl until pale yellow and smooth, 2 to 3 minutes. Stirring constantly, gradually pour half of the hot milk mixture into the egg yolk mixture, then stir the yolk mixture into the milk mixture remaining in the pan. Over medium heat, stir the milk mixture constantly until thickened, about 2 minutes. Strain the sauce into a medium bowl. For extra coconut flavor, add the 1/2 cup flaked coconut (I prefer it smooth!). Let cool to room temperature, then cover the bowl and chill until cold. (I like the sauce at room temp.).
Wontons: Place a heaping teaspoonful of the filling in the center of one of the wonton wrappers. (Keep the remaining wrappers covered with a damp kitchen towel to prevent them from drying out.) Moisten the edges of the wrapper with a fingertip dipped in water, then fold the wrapper in half to form a triangle. Pinch the edges together firmly to seal. Pull the opposite corners of the base of the triangle, moisten one of the corners with water, and press the two corners firmly to seal. Repeat with the remaining wontons and filling, keeping the folded wontons covered with a damp kitchen towel to prevent them from drying out.
Pour enough vegetable oil into a wok or 2 quart saucepan to come to a depth of 3 inches. Heat the oil over medium heat to 350°F Slip a few of the wontons into the oil and fry, turning occasionally, until golden brown, 2 to 3 minutes. Remove with a slotted spoon and drain on paper towels. Repeat with the remaining wontons. Serve hot or cold, with the coconut cream sauce.