Clean and cut ripe mangoes into bite size pieces. (Refer Note 1) Put three quarters of the sliced mangoes in a mixer or blender jar along with 2 tablespoons of sugar. Blend into a fine pulp and set aside. (Refer Note 2 & 3)
In a heavy bottom sauce pan, pour 2 cups of whole milk. Add sugar and salt and heat it on medium high heat.
Meanwhile, make cornstarch slurry by mixing in cornstarch with 3 tbsp of milk. Make sure it is mixed well and no lumps are seen. (Refer Note 4)
Add cornstarch slurry before the milk starts boiling. Reduce the heat to medium low and stir continuously. Whisk it well that there are no lumps in it.
Turn off the heat when the milk starts to thicken and the spoon is coated with milk mixture.
Stir in 1 teaspoon of vanilla extract and allow the custard to cool off to room temperature.
Once the custard is cool, add 1 cup mango pulp and blend until well combined.
Layer the bottom of a serving bowl with sliced mangoes and fill half of the bowl with mango custard. Cover and refrigerate it for 1 hour.
In a medium size bowl, add 1 cup heavy whipping cream and beat on high until soft peaks appear. Then whisk in 1 cup mango pulp and combine well. Keep the mango cream cool until the final layering.
Take out the mango custard from fridge after an hour. Add 1 to 2 tbsp of mango slices over cooled mango custard and fill the top with mango cream. Cover and freeze it for 3 to 4 hours. Serve chilled with fresh mango slices.