- Chop chocolates, set aside.
- Preheat an oven to 350F. Coat a pie plate with cooking spray.
- To make a crust , place the graham cracker in a processor and keep on proceeding until ground perfectly. Add water and butter, further process it until mix together finely and make a crunchy texture, turn out the mixture into the bottom of pie plate as it is up about 1 inch from every side. Now bake for 10 minutes, cool it.
- Prepare the filling by combining gelatin with water, leave for 2 minutes. Place in oven, let it cook on high heat for 40 seconds until it's dissolved completely.
- In a saucepan, finely combine cornstarch, sugar, cocoa powder and sauce also add milk gradually and beat it with the help of whisk until smooth, add remaining milk, cook on medium heat. Whisk it time by time until mixture is thickened and boiled; at least 10 minutes.
- Add chocolate and vanilla; stir gently; until chocolate is melted, stir in gelatin mixture. Spread over the pie crust and cool it for 3 hours.
- Whip cream in a small bowl just to halfway stiff peaks, then add sugar and whipping it constantly until it holds a soft peak. Spread all over the edges of pie filling. You can store into the refrigerator more than 2 days.