Whisk the dry ingredients first. In a medium bowl, whisk cocoa powder, protein powder, and salt until there are no lumps.
This helps everything blend smoothly later.
Stream in the milk. Slowly add about half the milk while whisking to form a smooth paste. Then whisk in the remaining milk until fully combined.
Add flavor and sweetness. Stir in vanilla and your sweetener of choice. Taste and adjust now; it won’t get sweeter as it chills.
Add the chia seeds. Sprinkle chia seeds over the liquid, whisking as you go to prevent clumping.
Keep whisking for 30–60 seconds.
Rest and re-whisk. Let the mixture sit for 10 minutes, then whisk again to break up any settling seeds. This step ensures an even, pudding-like texture.
Chill. Cover and refrigerate for at least 2 hours, ideally overnight. It will thicken significantly.
Adjust the texture. If it’s too thick, stir in a splash of milk.
If it’s too loose, add another teaspoon of chia and chill 15–20 more minutes.
Serve. Spoon into bowls or jars, add toppings, and enjoy cold.