Grease an 8” round cake pan. Cut a circle of wax paper to fit bottom of the pan. Insert the wax paper and grease it as well.
Place 1 cup of the chocolate chips and the butter in a medium sized microwave-safe bowl. Microwave in 30 second increments, stirring after every 30 seconds, until the butter is melted. Stir until the chocolate chips melt and combine with the butter.
Stir in the sugar, salt, coffee, and vanilla.
Switch to a whisk and whisk in the eggs until the mixture is smooth.
Add the cocoa powder and whisk just until combined.
Spoon the batter into the pan. Bake for 25 minutes. The top will form a thin crust.
Remove from the oven and cool in the pan for 5 minutes. Loosen the edges of the cake from the pan with a sharp, thin knife. Invert onto a serving plate (note: the edges may crackle a bit). Allow the cake to cool completely before proceeding.
Make the ganache – combine the remaining 1 cup chocolate chips and heavy whipping cream in a microwave-safe bowl. Heat until the cream is hot but not bubbling. Stir until the chocolate chips melt and the mixture is very smooth. Pour the ganache over the top of the cake, spreading just to the edges.
Allow the ganache to set for several hours (refrigerated or not) until ready to serve.