1. Spray two micro-wave safe mugs with non-stick oil. Evenly divide the following ingredients : cake mix, egg whites / substitutes, sour cream, and baking powder.
2. Add 2 tbsp water to each mug, and mix until uniform consistency. Stir 1/2 tsp chocolate chips into each mug
3. Microwave each mug for 1 minute 45 seconds or until set.
4. Run a knife along the edges to help separate the first cake from its mug. Firmly place a plate over the mug and flip so that the plate is on the bottom. Gently shake mug to dislodge cake onto the plate. Do the same to the second mug.
5. Allow to cool for about 15 minutes.
6. You can also opt to leave the cakes in the mugs.
7. In a small bowl, combine powdered sugar with milk, and stir until smooth. Drizzle over cooled cakes and top each with 1/2 tsp of the remaining chocolate chips. Serve and enjoy!