1. Heat the oven to 180C/160 fan/gas 4 and grease and line three 9-inch cake tins. In a large bowl, cream the butter and sugar until soft and light. Add the eggs, a little at a time, beating well to fully incorporate. Combine the flour, malt drink, Dr. Oetker Cocoa Powder and Dr. Oetker Baking Powder with a pinch of salt in a small bowl. Fold into the butter and egg mixture, then add the yogurt, melted Dr. Oetker Milk Chocolate and 100ml hot water. Stir until well combined then divide between the tins. Bake for 25-30 mins until a skewer inserted into the middle of the cake comes out clean.
2. To make the marshmallow frosting, combine the egg whites, caster sugar, Dr. Oetker Cream of Tartar and Dr. Oetker Glucose Syrup to a large bowl. Set this over a pan of just simmering water (don’t let the bowl touch the water) and whisk with electric beaters until the sugar has dissolved and the mixture is warm. Remove from the heat and continue whisking until fluffy and doubled in volume. Beat the butter on a high speed until light, then add the icing sugar and Dr. Oetker Madagascan Vanilla Extract and continue beating for about 5 mins until fully incorporated. Add the marshmallow mixture and beat on a high speed until fluffy. Pop in the fridge until needed.
3. When ready to decorate the cake, place a little of the frosting on a cake board. Top with the first layer of sponge, then spread with a few tbsp of frosting. Repeat this process until all the layers are used up. Crumb coat the cake by using about one-third of the remaining frosting to lightly cover the cake as evenly as possible. Discard any unused crumb frosting. Refrigerate for at least 1 hr. Use the remaining frosting to cover the cake, using a cake scraper or palette knife to create an even surface. Refrigerate for a further 1 hr.
4. Meanwhile, make the chocolate bark by melting each chocolate separately, either in small glass bowls set over simmering water or in the microwave, stirring frequently. Line three baking trays with baking parchment. Pour about half of the Dr. Oetker 72% Extra Dark Chocolate onto one of the trays, then drizzle with the Dr. Oetker White Chocolate and Dr. Oetker Milk Chocolate. Repeat for the other kinds of chocolate, then sprinkle with the Dr. Oetker Glamour and Sparkle Sprinkles and refrigerate to set.
5. To decorate, drizzle the edge of the top of the cake with the remaining melted dark chocolate, allowing it to drip down the sides – make sure the chocolate is completely cool at this stage. Pile the middle of the cake with the Dr. Oetker Chocolate Stars, marshmallows, candy canes, meringue and chocolate kisses. Serve immediately.