Start with a good selection of coffee, something that already tastes good. This can be used to improve otherwise ordinary coffee, but it cannot mask disgusting swill. If your coffee is disgusting swill the only help for it is to poison some plant with it.
Add two heaping tablespoons of Cocoa Powder.
Add a third to a half teaspoon of Cayenne pepper. Yes, you read that right.
This produces a wonderful drink when stirred well. If you’re so inclined, you can also add some unsalted, grass fed butter to make it a shade of Bulletproof. I do this some days.
The reason I do this: I like Hot Cocoa (not sugary Hot Chocolate), and I like Coffee. The Aztec used to make a cocoa concoction with hot peppers, and I like spicy food. It goes together well, like Donkey Kong and barrels. You are basically making a “Mocha” coffee without a bunch of sugar and then kicking it up a notch.