Mix cocoa, cornstarch and beaten egg yolks, then sugar and salt, add the milk gradually, while stirring in a pot over medium-high heat on your stove top.

Cook until it's thick. Whisking it until it's smooth.

Cream pies take some time to thicken. So stir for (10-15) mins. Using a heavy bottom pan really helps this pie. Just keep it up until it thickens, add the vanilla in after you take the pan off the heat. Pour into a pre baked pie shell. Put it in the fridge to chill, add whipped cream if you like and top with chocolate shavings.