Whisk 3 cups of milk, turbinado, and cocoa in a ceramic or anodized stainless steel saucepan over medium-high heat. Bring to simmer. Remove from heat.

Whisk 1 cup milk, arrowroot, salt, egg yolks, and vanilla 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 (~3 minutes).

Split between 8 cups/bowls/ramekins. (Optional: cover with parchment paper or plastic wrap. I don't do this because I like the film that forms on top of the pudding. Try both and see which you like.)

Refrigerate for at least 6 hours.