Step 1

Whisk together with a fork, the flour, sugar, cocoa powder, baking powder and salt until well combined in mug.

Step 2

Add in the melted butter, milk, egg and vanilla. Whisk well to combine, making sure to mix in the flour mixture in the bottom.

Step 3

Place the semi-sweet chocolate chips in the center of the mug. Drizzle the tablespoon of water right on top of the batter.

Step 4

Cook in microwave for 1-2 minutes or until the cake rises to the top, the edges look set. The center will looks slighty wet and shiny but not raw, and sticks slightly to the finger when touched.

Step 5

Let it cool for about 5 minutes.