Method

  1. Grease a 15cm/6in silicone microwaveable cake mould with a little oil and line the bottom with a circle of baking paper.
  2. Mix the sugar, flour, cocoa, espresso powder, baking powder and salt in a bowl. In a jug, whisk together the oil, egg and hot water.
  3. Incorporate the wet ingredients into the dry ingredients, mixing thoroughly until you have a lump-free batter. Pour the mixture into the cake mould and tap a few times on the work surface to dissipate any air bubbles. Cover with cling film.
  4. Microwave on full power (800W) for 5 minutes.
  5. Remove the cake from the microwave and check if it’s cooked: poke a skewer into the middle, and if it comes out clean the cake is cooked. Leave the cake to stand for 5 minutes while you make the ganache.
  6. To make the ganache, melt the chocolate on half power (600W) for 2 minutes, stirring often to ensure it does not burn. Remove from the microwave and add the cream, stirring until smooth and glossy.
  7. To decorate, melt the white chocolate in a small bowl on half power (600W) for 1 minute, stirring halfway through, until smooth and runny.
  8. Turn out the cake onto a serving plate and leave to cool for a few minutes.
  9. Spread the ganache over the cake. Using a teaspoon, drizzle the white chocolate in thin parallel lines across the ganache. Drag a cocktail stick or skewer up and down, pulling through the chocolate to give a feathered effect.

Ingredients

For the microwave cake

  • 90g/3¼oz light brown sugar
  • 70g/2½oz self-raising flour
  • 2 tbsp cocoa powder
  • 1 tsp espresso coffee powder
  • 1 tsp baking powder
  • pinch salt
  • 50ml/2fl oz sunflower oil, plus extra for greasing
  • 1 large free-range egg
  • 55ml/2fl oz hot water

For the chocolate ganache

  • 75g/2⅔oz dark chocolate, broken into pieces
  • 3 tbsp double cream

To decorate

  • 40g/1½oz white chocolate, broken into pieces