4 tablespoons of unsweetened cocoa powder
2 to 4 tablespoons of sugar (depending on how sweet you like it)
Pinch of salt
2 cups milk or half + half (or your favorite milk substitute)
1/4 – 1/2 teaspoon of vanilla extract

Whisk together the cocoa, sugar, salt, and about 2 tablespoons of milk in a small saucepan over medium-low heat until cocoa and sugar are dissolved. Turn up the heat to medium and whisk in the rest of the milk. Keep whisking occasionally until heated through. Stir in the vanilla and serve.