Preheat the oven to 180C/350F. Grease three 8-inch cake pans and set aside.
In a large mixing bowl, add the flour, cocoa powder, espresso powder, sugar, and baking soda. Add the vanilla extract, vinegar, oil, and brewed coffee and mix until a thick batter remains.
Distribute the batter evenly amongst the three cake pans. Bake the cakes for 25-27 minutes, or until a skewer comes out mostly clean.
Let the cakes cool completely, before slicing each cake into three thin pieces. Place a single layer on a flat surface, and spread with a thin layer of frosting. Add the second piece of cake, followed by more frosting. Repeat the process until you have all nine pieces of cake frosted and stacked. Spread the remaining frosting around and all over the cake. Let it sit for 30 minutes, before slicing and serving.
Notes
You can simply leave this as a 3 layer cake. Simply omit slicing each cake into three pieces. TO STORE: Leftover cake can be stored in the refrigerator, covered. It will keep well for up to 2 weeks. TO FREEZE: Place slices of the cake in a sealable container and store in the freezer for up to 6 months.