Preheat the oven to 180°C (350°F) and line 2x 22cm diameter (9 inch) round cake tins with oil and parchment paper.
Add the eggs, sugar, and oil to a bowl of an electric mixer fitted with a whisk attachment and beat at medium-high speed until well combined.
Sift together the flour, cocoa powder, salt, and bicarbonate of soda. Add the dry ingredients to the egg mixture, and beat at medium speed until just combined.
In a jug mix together the buttermilk, brewed coffee, and vanilla. Slowly pour this into the egg and flour mixture, with the motor running at low speed. Mix until combined and lump-free.
Pour the cake batter into the prepared cake tins and bake in a preheated oven for about 40 minutes or until a skewer inserted into the center of the cake comes out clean. Once baked allow the cakes to cool in their tins for about 10 minutes before turning them onto a wire rack to cool completely.
This is optional but recommended for easier decorating! Wrap the cooled cake layers in plastic wrap and place them in the fridge overnight.
Cream Cheese Frosting
Add the icing sugar and room temperature butter to a bowl of a stand mixer fitted with a paddle attachment. Beat at medium speed until the mixture resembles fine breadcrumbs.
Add the cubed cream cheese and beat at medium-high speed until the frosting is well combined. Scrape down the sides of the bowl using a rubber spatula and mix again for about 2 to 5 minutes until the frosting is light and fluffy. Add the frosting to a piping bag.
Decorating
Use a sharp knife to trim the domed tops off of the cake layers if necessary.
Secure the first cake layer onto a cake plate with a bit of frosting. Pipe a layer of frosting over the surface of the cake and smooth this out with a spatula.
Place the second layer of cake onto the first layer with the cut side facing down.
Pipe the frosting over the top and sides of the cake and use a spatula or cake scraper to even this out. Place the cake into the fridge for about 30 minutes to firm up.
Pipe another layer of frosting around the entire cake and then use an offset spatula to swirl the frosting. Serve and enjoy!