1. In large saucepan boil 2 cups of milk, sugar and unsweetened cocoa powder, until it thickens, remove from heat and keep it aside.
2. In a bowl combine the corn starch, water, ½ cup of milk, egg yolks and vanilla extract, let it mix well.
3. Put the saucepan back on the heat and add the egg mixture in the chocolate sauce, cook the mixture for few minutes.
4. Then add the marshmallow and stir until the entire marshmallow has been dissolved and you get a thick sauce like consistency.
5. Pour the mixture in the pie dish which has been lined with the pie crust.
6. Cover the pie dish with cling wrap and refrigerate for 2 hours.
7. In a bowl whip the sweeten cream along with the powdered sugar
8. After 2 hours top the chocolate pie with whipped cream and sprinkle some chocolate shavings.
9. Serve the delicious Chocolate Marshmallow Pie after a hearty meal.
You can adjust the sweetness of the chocolate as per your taste.