Preheat the oven to 350F degrees and adjust the oven rack to the middle position. Line a muffin/cupcake pan with 5 cupcake liners.
In a small mixing bowl, whisk together the almond flour, arrowroot flour, coconut flour, tapioca flour, cocoa powder, coconut sugar, baking powder and soda, and salt.
In a medium mixing bowl, add the egg, melted coconut oil, coconut milk, vinegar, and vanilla extract. Whisk until completely combined.
Sprinkle the dry ingredients over the top of the wet ingredients. Stir until no dry streaks remain. Add the hot coffee (or water), and stir until combined.
Bake the cupcakes for 14 to 15 minutes, or until a toothpick inserted in the middle comes out mostly clean. Cool the cupcakes in the pan set on a wire cooling rack for 5 minutes, then transfer the cupcakes to the rack to cool completely.