Preheat the oven to 375°F. Lightly grease a metal 8″ round cake pan; cut a piece of parchment to fit, grease it, and lay it in the bottom of the pan.
Put the chocolate in small chopped pieces and the Coconut oil in a microwave-safe bowl, and heat until everything is melted, reheating briefly if necessary. You can also do this over a burner set at very low heat. Transfer the melted chocolate to a mixing bowl.
Stir in the sugar, salt, espresso powder, vanilla and almond flour. Espresso enhances chocolate’s flavor much as vanilla does; using 1 teaspoon will simply enhance the flavor, while 2 teaspoons will lend a hint of mocha to the cake.
Add the eggs, beating briefly until smooth. Add the cocoa powder, and mix just to combine
Spoon the batter into the prepared pan.
Bake the cake for 25 minutes; the top will have formed a thin crust, and it should register at least 200°F on an instant-read thermometer inserted into its centre.
Remove it from the oven, and cool it in the pan for 5 minutes.