Whisk Whole Milk (3/4 quart), Pure Cane Sugar (3/4 cup) and Unsweetened Cocoa Powder (2/3 cup) in a ceramic or anodized stainless steel saucepan over medium-high heat. Bring to simmer. Remove from heat.
Whisk Whole Milk (1/4 quart), Arrowroot (8 teaspoon), Salt (1/2 teaspoon), Large Egg (6), and Pure Vanilla Extract (4 teaspoon) in a medium to large bowl.
Temper the egg mixture by whisking while slowly adding the cocoa mixture.
Pour entire mixture back into the saucepan and whisk constantly over medium-high.
When it comes to a full boil you will notice the mixture thickening. Reduce the heat to simmer and continue whisking until thick.
Split between 8 cups, bowls or ramekins.
Refrigerate for at least 6 hours.
Serve with Whipped Cream (3/4 cup) and enjoy!