Preheat the oven to 150ºC.
Grease three round tins and line with parchment paper.
Fit the Creaming Beater to the machine.

Add milk, water, oil, vanilla and egg into the 5L Mixer bowl.
Attach the 5L Mixer bowl to the machine. 
Start the machine on speed Min and gradually increase speed.
Mix on speed 1 for 20 seconds until combined.
Add flour, cocoa powder, baking powder, bicarbonate of soda, caster sugar and salt into the 5L Mixer bowl.
Start the machine on speed Min and gradually increase speed.
Mix on speed 3 for 30-40 seconds until combined.
Transfer the mixture into one of the prepared tins.
Bake at 150ºC for 40 minutes.
Remove from the oven and let cool for 10 minutes.
Turn onto a wire rack to cool completely.

Add cocoa powder, espresso powder and hot water into a small bowl.
Stir to combine.
Set aside and let cool.
Add white chocolate into a heatproof bowl.
Microwave until melted, stirring every 10-20 seconds to prevent burning.
Set aside and let cool.

Fit the Creaming Beater to the machine.
Add milk, oil, vanilla and eggs into the 7L Mixer bowl.
Attach the 7L Mixer Bowl to the machine, fit the splashguard.
Start the machine on speed Min and gradually increase speed.
Mix on speed 1 for 20 seconds until combined.
Add flour, caster sugar, baking powder and salt into the 7L Mixer bowl.
Start the machine on speed Min and gradually increase speed.
Mix on speed 3 for 30-40 seconds until combined.
Transfer half of the mixture (400 g) into a clean large bowl and set aside.

Transfer the cooled coffee mixture from the small bowl into the 7L Mixer bowl.
Start the machine on speed Min and gradually increase speed.
Mix on speed 3 for 20-30 seconds until combined.
Spoon the coffee mixture into one of the cake tins and set aside.

Transfer the melted white chocolate into the large bowl containing the remaining half of the batter.
Stir to combine.
Spoon the mixture into the second, round tin.
Place both tins in the oven.
Bake at 150ºC for 35-40 minutes until a skewer inserted comes out clean.
The white chocolate cake may take a few minutes longer to bake.
Remove from the oven and let cool for 10 minutes.
Turn onto a wire rack to cool completely.

Add instant coffee and hot water into a small bowl.
Stir to combine and set aside.
Add white chocolate into a clean heatproof bowl.
Microwave until melted, stirring every 10-20 seconds to prevent burning.
Set aside and let cool.

Retrieve, clean the 7L Mixer bowl and fit the Creaming Beater.
Add butter, vanilla and salt into the 7L Mixer bowl.
Attach the Mixer Bowl to the machine, fit the splashguard.
Start the machine on speed 1 and gradually increase speed.
Mix on speed 3 for 30 seconds.
Scrape down the side of the bowl with a spatula.
Add 1/3 icing sugar and milk into the 7L Mixer bowl.
Start the machine on speed 1 and gradually increase speed.
Mix on speed 4 for 30 seconds.
Scrape down the side of the bowl with a spatula.
Add 1/3 icing sugar and milk.
Mix on speed 4 for 30 seconds.
Scrape down the side of the bowl with a spatula.
Add remaining icing sugar and milk.
Mix on speed 4 for 30 seconds until smooth.
Add a little milk if the mixture is too dry and mix again.

Divide the content of the 7L Mixer bowl between three medium bowls.
Transfer the cooled white chocolate into one of the bowls.
Stir to combine.
Transfer the cooled coffee mixture into the second medium bowl.
Stir to combine.
Add cocoa powder and milk into the third medium bowl.
Stir to combine.

Use an adjustable sponge cake slicer to level the top of each cake by removing a very thin layer.
Using the cake slicer, cut each cake in half.
Place the cake board or drum in the centre of the cake turntable.
Add a small amount of chocolate buttercream to the board to help the cake stick to the board.
Place the first chocolate sponge on top of the cake board, ensure it is central.
Top with a thin layer of chocolate buttercream.
Use an angled spatula to level the surface.
Place the second chocolate sponge on top.
Top with a thin layer of chocolate buttercream.
Use an angled spatula to level the surface.
Repeat this layering process on top with the coffee cake layers and coffee buttercream.
Then repeat this process with the white chocolate layers and white chocolate buttercream.

Once the cake is assembled use the remaining buttercream to create the ombre effect:
Transfer the remaining buttercream into three separate piping bags.
Start at the bottom of the cake with the chocolate buttercream.
Pipe two rings of chocolate buttercream around the outside of the chocolate cake layer.
Then pipe two rings of coffee buttercream around the outside of the coffee cake layer.
Repeat this process with the white chocolate buttercream, then continue up on top of the cake with the white buttercream.
Dip an angled spatula into a jug of hot water, remove the excess.
Hold the spatula flat against the side of the cake so it touches the buttercream.
Use the spatula to scrape round the side of the cake, turning the turntable as you work.
Remove the excess buttercream from the spatula, save it for later – you can re-use for piping decoration if you are careful.
Clean the angled spatula in the hot water.
Repeat this scraping method until you have a smooth straight surface.
Clean the angled spatula again.
Scrape across the top of the cake to create a smooth, flat top.
Remove any excess buttercream from the spatula and repeat until smooth and flat.
Transfer the cake to the fridge for 30 minutes – 1 hour until the buttercream is set and firm.
Transfer any remaining buttercream into piping bags fitted with your choice of decorative tip (plain tip, star or open star) and set aside.

To finish
Add the whipping cream into a clean heatproof bowl.
Microwave in 20 seconds intervals until steaming, be careful not to boil the cream.
Set aside and let cool slightly – if too hot, it will split when the chocolate is added.

Add the dark chocolate into the cream.
Stir occasionally until melted and smooth.
Transfer the chocolate ganache into a piping bag and set aside.

Retrieve the cake from the fridge.
Place on the cake turntable.
Use scissors to cut the piping bag open by approx. 5 mm.
Start piping the ganache along the top edge of the cake so that it drips down the side – test a small area first to check the consistency.
If it is too runny, allow the ganache to cool slightly and try again.
Create the drip effect around three quarters of the top of the cake, leaving the rest plain.
Place the cake in the fridge for 30 minutes to set the ganache.

Remove the cake from the fridge
Pipe the remaining buttercream on top of the cake, alternating between flavours.
Finish with your choice of chocolate decorations.

To serve
Serve immediately or refrigerate until ready to serve