Preheat oven to 350°F. Line 3 8" round baking pans with parchment rounds, spray with oil and lightly dust with flour. Set aside. For a smaller cake- Fill 2 6" cake pans. Will have enough extra batter to make 24 cupcakes which can freeze and enjoy later.
Using a food processor, pulse the chocolate until you have finely chopped chocolate pieces. Combine the chocolate with the hot coffee and let it melt for several minutes. Add vanilla and stir until well blended. Set aside to cool slightly.
In a separate bowl, whisk the eggs and the oil until combined. Whisk in the sour cream to the egg and oil mixture until combined. Slowly add the chocolate mixture and whisk to combine.
In a mixing bowl or stand mixer, combine the flour, sugar, salt, cinnamon, espresso powder, and baking soda and mix for 10 seconds on lowest setting.
Beat in the wet ingredients, in 3 batches. Mix until just combined, do not over mix the batter. This is create a dense cake.
Divide into two or three cake pans (depending on the size cake pan you are using). Bake for 35-40 min for 8" cake, 30-40 minutes for 6" cake, 15-18 minutes for cupcakes or until toothpick inserted in the middle of the cake comes out with a few crumbs. TIP: set timer for minimum time and check doneness by inserting a toothpick.