Preheat your oven to Spray three 8-inch cake tins with oil spray and line the bottom with baking paper. Set aside.
Add the flour, baking soda, baking powder, salt and cocoa powder to a large microwave bowl. Use a whisk to combine. Set aside.
Add the oil and both sugars into a separate large mixing bowl. Use an electric hand mixer to whip until pale and fluffy. Add the eggs one at a time, mixing each time. Make sure you’re also scraping down the bowl. Add the coffee Kahlua mixture and milk and whisk to combine. Don’t worry, you won’t get drunk from the cake, the alcohol bakes off when the cake goes into the oven but you end up with a rich coffee flavour.
Add 1/2 of the dry ingredients and whisk until well combined. Then add the remaining dry ingredients and repeat.
Distribute the batter in the three cake tins. Bake for 40 minutes and then allow to cool completely.
Add your softened butter to the bowl of a stand mixer fitted with the paddle attachment. You can also use a hand mixer for this recipe, but if you do use a hand mixer, just make sure your bowl is large. Mix the butter on low speed to begin with, then switch to the highest speed and mix for 5 minutes until the butter is fluffy and turns pale in colour.
Stop your mixer and scrape down the side of the bowl using a spatula. Add the icing sugar, vanilla extract and coffee shots and mix again on low speed. LOW SPEED PEOPLE! The last thing you need is to end up in a sugar dust storm! (I’m speaking from experience…)
Once all the sugar has been incorporated, it’s safe to turn your mixer up to high speed. Continue beating on high speed for about 5–6 minutes, or until the butter turns pale in colour and becomes fluffy again.
Filling the cakes
Use a large serrated knife or cake leveller to trim the top off each cake.
To crumb coat your cake, add a dab of frosting onto an 8” cake board or flat serving plate. Use a small offset spatula to spread the frosting around before adding the first cake layer. Gently press down the centre of the cake layer to make sure it’s stuck to the frosting underneath.
Add frosting to a piping bag and frost a ring around the top of the cake. Fill the centre with more frosting. Use your small offset spatula to smoothen out the frosting before you add the next layer of cake. Repeat with the remaining layers.
Add more frosting around and top and sides of the cake. Use the small spatula to smoothen out the top and sides of the cake, taking care to fill in any gaps in between each layer of cake.
Use a cake scraper (otherwise known as a bench scraper) to smoothen out the frosting on the sides and top. Get it as neat as you can. This should just be a neat, thin layer of frosting which is aimed at trapping any cake crumbs so that random bits of cake crumbs don’t show up on the final layer of frosting. Chill for 2 hours or overnight.
Add a final layer of frosting and smoothen out using the same technique as crumb coating the cake.
Drizzle the top with chocolate sauce. Fit the end of a piping bag with a Wilton 6b piping tip and pipe swirls around the top of the cake. Finish by sprinkling the top with sprinkles and adding coffee beans to the sides of the cake.