Immediately whisk the cocoa powder, sugar and sea salt into boiling water.
Once the mixture has formed a paste, whisk in in the whole milk (you can add more milk to make it less rich).Once it’s nearing your ideal temperature, add the vanilla extract. Continue to stir and heat until the homemade hot chocolate mixture over medium heat until it’s very hot – but be careful not to bring it to a boil.
Remove from heat, pour into your favorite mugs and top with your favorite toppings.You can add a little milk (or heavy cream to make it even creamier) to the homemade hot chocolate if you need to cool it down quickly for eager little ones (like mine).