Crack open the egg in a small bowl and beat well.
Peel the skin off the apples and remove the stem. Cut the apple into ⅛ and cut to pieces, about 3 mm.
Place the apples in a bowl and add in sugar, cinnamon, salt, flour, and lemon juice. Mix well and let it rest.
Melt the butter in a frying pan and pour in the apples from Step 3. Stir and cook for about 5 minutes in medium heat, making sure that the apples do not get burnt. Remove the pan from heat and let it cool.
Spread the wonton wrapper and pour in a small amount of the filling from Step 4. Brush on the beaten egg to all four corners and fold into a pyramid. Make sure that the wrapper is properly sealed.
Place the pyramid shape wontons onto a baking sheet or aluminum foil. Bake for 10 minutes in the toaster oven. Remove the wonton from the oven and sprinkle on powdered sugar to finish. Enjoy!