Preheat your oven to 350°F (175°C) and prepare two 8-inch round cake pans by spraying them with nonstick spray and lining the bottoms with parchment paper.

In a large mixing bowl, sift together the all-purpose flour, black cocoa powder, sugar, baking powder, baking soda, and salt. Set aside.

In another bowl, whisk together the buttermilk, canola oil, eggs, and vanilla extract until smooth.

Pour the wet mixture into the bowl with the dry ingredients and gently stir until just combined. Add hot coffee gradually.

Divide the batter evenly between the prepared cake pans and bake for about 30-33 minutes, or until a toothpick comes out clean.

Allow the cakes to cool in the pans for about 10 minutes before transferring them to wire racks.

To make the blackberry compote, combine fresh blackberries, sugar, lemon juice, cinnamon stick, and lemon zest in a saucepan and cook until the berries break down.

In a mixing bowl, beat the softened cream cheese and butter until creamy, then add the powdered sugar and black cocoa powder, mixing until smooth.

To assemble the cake, level the cooled layers, spread a layer of blackberry compote on the first layer, and stack the second layer.

Spread a final layer of frosting on the entire cake and decorate as desired.