Chocolate and ginger mug microwave cake recipe ¼ tsp ginger powder 1 egg 3 tbsp milk 3 tbsp butter, melted 2 pieces of stem ginger in syrup, finely chopped, plus a drizzle of syrup Using a very small sieve or a tea strainer, sieve the dry ingredients into the largest mug you have. Use a fork to whisk in the remaining ingredients, along with a very small pinch of salt. Place in the microwave for 3 minutes on maximum power, about 1,000 watts. Leave to cool until the cake settles and stops rising. Run a knife around the edge of the mug and transfer the cake onto a plate. Serve with ice cream or custard, and a drizzle of ginger syrup