Preheat the oven to 180C / 160C Fan / Gas Mark 4. Line four 20cm cake tins with non-stick parchment paper. 

Make the Dr. Oetker Chocolate Cake Mix according to package instructions. 

Divide the mix evenly between the tins. Bake for 25-30 minutes or until a skewer inserted in the centre comes out clean. Allow to cool fully. 

Once cooled, use a serrated knife to level the tops of the sponges. 

To make the buttercream, beat together the icing sugar, the cocoa powder, unsalted butter, melted chocolate and vanilla extract until smooth. Stir in a little hot water to loosen the buttercream if needed. 

To assemble the cake, place the first sponge layer on a cake board or serving plate. Spread over some of the buttercream and place the next sponge on top. Continue to stack and spread buttercream on each of these sponges. 

Use a palette knife or offset spatula to spread the buttercream over the top and sides of the cake, making sure to fill in any of the gaps. Refrigerate the cake for 30 minutes to set. 

Once set, spread over more buttercream to cover any crumbs and smooth the icing. Allow the cake to set in the fridge for a further 5-10 minutes. 

To make the ghosts, melt the white chocolate according to package instructions. 

Line a baking tray with parchment paper. Spoon small blobs of the melted white chocolate onto the lined tray and use the back of a teaspoon or a paintbrush to spread the chocolate to make teardrop shapes. You can make a variety of different sizes to add to the effect. 

Continue until all the white chocolate is used. Place in the fridge to set for the 5 minutes. 

Once set, use a toothpick or small paintbrush to add eyes and a mouth using the Dr. Oetker Extra Strong Black Gel Food Colour. 

To make the eyeballs, roll small pieces of white fondant into small balls. Using a toothpick or small paintbrush, add a dot of Dr. Oetker Extra Strong Black Gel Food Colour to the centre for the pupil. 

To decorate the cake, use an angled palette knife to gently lift the ghosts off the parchment paper. Press them gently onto the side of the cake and stagger them around the sides. 

Add the eyeballs in pairs of two and dot them around the sides of the cake. 

Serve and Enjoy!