Combine the cocoa powder, sugar, and water in a medium saucepan. Heat over medium low. Stir until cocoa powder and sugar are dissolved, about 2 minutes.
1 cup unsweetened cocoa powder, 1 cup sugar, 1 cup water
Add the peanut butter and vanilla and continue stirring while syrup heats, about 5 minutes.
When all ingredients are dissolved completely, and the sauce has slightly thickened, about 10 minutes total, remove from the heat. Let cool slightly.
Serve warm drizzled over ice cream or dessert, stirred into milk, or just eat it with a spoon!
Notes
Consistency: if your sauce is too thin for your liking, cook it a bit longer on the stove top or add a bit more peanut butter. Too thick, stir in a bit of water until it is to your liking.
Vegan/dairy free: check the cocoa powder label for dairy ingredients if you are vegan or dairy free.
Raw cacao powder: feel free to swap the cocoa powder for raw cacao powder.
The peanut butter: creamy or chunky peanut butter both are great! Just depends on your preference.
The salt: if you're not using salted peanut butter, go ahead and add a pinch of salt to your sauce.
The sugar: the consistency will change if you swap the sugar for maple syrup or agave, as they are in liquid form. Start by adding less water to the sauce and/or cooking the sauce a bit longer to let it thicken.
Sweetness: taste the sauce as you go and adjust the sweetness to your liking. If you prefer a sweeter sauce, add a bit more sugar. For a less sweet option, reduce the sugar quantity or opt for a sugar-free alternative.