Mix all the dry ingredients first. Add in wet ingredients and mix well.
Pour this into a microwave safe bowl, place chocolate chunks and marshmallow over it and microwave it on high power for 35 to 50 seconds.
Remove it and let it cool a bit.
Serve.
Notes
1)This cake takes only few seconds to bake, mine took 45 seconds to make. So keep a eye on it.
2) This cake will be fudgy and dense. Taste great with a scoop of vanilla icecream
3)My Microwave has a high power of 800 watts.