Galaxy cake - Good Food Middle East

Ingredients

• 250g unsalted butter
• 200g dark chocolate (70% cocoa solids)
• 350g light soft brown sugar
• 200g self-raising flour
• 1 tsp bicarbonate of soda?
• ½ tsp salt
• 4 large eggs
• 300ml tub sour cream
• 100ml strong hot coffee (double shot of espresso)
• 250g fun size bag of mini Mars Bars
• 397g can Nestlé Carnation Caramel
• 1 tsp flaky sea salt
• 400g unsalted butter, softened at room temperature
• 800g icing sugar
• 2 tsp vanilla bean paste
• 4 tbsp whole milk
• black, blue, purple and green food colouring gel
• navy and silver lustre dust
• edible metallic pearlescent white paint
• silver pearl balls
• thin paintbrush
• cake scraper