Preheat oven to 350F. Prepare two 8" round baking pans with baker's spray or GOOP.
Combine chocolate, cocoa powder and three tablespoons of coffee in a heat-proof bowl. (The best way to do this is the brew coffee and place 2 cups into a medium bowl. Remove 3 tablespoons. You will use the remainder in a moment.)
Place bowl over a pot of simmering water, gently stir until melted and combined. Remove from heat. (You can also melt in microwave. Heat for 30 seconds then switch to 10-second increments. Stir between each heating.)
In a large mixing bowl, combine flour, cinnamon, salt, baking soda and baking powder.
In another bowl, whisk together the vegetable oil, remaining coffee, avocado,and both sugars. Stir in the slightly cooled chocolate.
Add the wet ingredients to the dry ingredients. Whisk until fully combined and smooth, scraping the side of the bowls completely. (try to not over mix)
Divide batter between both baking pans. Bake in preheated oven for 45 minutes, until a toothpick inserted into center of cake comes out clean.
Allow to cool completely before frosting.
In a the bowl of an electric stand mixer, fitted with whisk attachment whisk butter and sugar on medium-high speed until very pale and fluffy or about five minutes.
Be sure to stop at least once and scrape the bowl.
With the mixer off, add in cocoa powder, vanilla and salt.
Turn mixer on low and blend for about 30 seconds.
One tablespoon at a time add in heavy cream.
Once all cream has been added and mixture is mostly combined, turn off the mixer and scrape down the sides of the bowl.
Now turn the mixer onto medium-high to high and whisk for 3-5 minutes or until mixture is lighter and fluffier. The frosting will be shiny and seem to have many large air bubbles throughout and this is exactly what we are going for. (You can smooth those out on the cake if so desired.)
Deep cocoa aromas emerge from a dense crumb bound by melted dark chocolate and mashed avocado. Pureeing the avocado until completely smooth prevents green flecks and distinct lumps from appearing in the baked layers. Mash the fruit thoroughly before mixing it into the liquid ingredients to ensure uniform fat distribution throughout the batter. Using fresh avocados yields superior emulsion stability compared to commercially processed purees, which often contain added acids or stabilizers that alter moisture retention. Kitchen equipment requirements demand two eight-inch round baking pans, an electric stand mixer fitted with a whisk attachment, and a heat-proof bowl for melting chocolate over a simmering water bath. When an electric stand mixer is unavailable, a handheld electric mixer operates adequately if operated carefully during the prolonged five-minute butter and sugar creaming stage. Standard baking spray or a homemade flour-and-oil paste prevents the cakes from sticking to the pans after forty-five minutes in a 350-degree Fahrenheit oven. Cool the layers completely on wire racks before applying the heavy cream and cocoa buttercream to prevent melting the fat content in the frosting.