In a large mug combine raisins, brandy (apple juice) and vanilla. Microwave for 30 seconds and allow to rest for about 5 minutes.
Whisk Egg while adding in milk and brown sugar. Add flour, oats, cinnamon and salt. Beat until smooth.
Pour batter into your mugs filling no more then half way. Sprinkle a 50/50 sugar/cinnamon mix over the top of the batter. Microwave for 1-1/2 - 2-1/2 minutes until the cake has risen and is firm.
Notes
If you don't have self rising flour just mix 1 Cup of flour, 3/4 teaspoon of baking powder and a little salt