Lightly brush the inside of your coffee cup with softened butter, or spray with non-stick baking spray.
In the cup, use a small whisk to combine the flour, sugar, cocoa powder, baking powder and salt.
Add the milk, melted butter and vanilla, and whisk until smooth. Sprinkle the top of the batter with the chocolate chips.
Microwave the cake on high for about 60-90 seconds, until the cake is puffed and set.Times will vary based on the wattage of your microwave. You may need more or less time depending on your microwave, as well as if you added other mix-ins to your cake batter. Mine is 1000W, and I found that 65 seconds was just right.
Let the cake cool for 1 minute, then top with a scoop of ice cream, salted caramel sauce and extra chocolate chips if you like, and serve immediately.
Keyword Chocolate Cake, High Altitude, Mug Cake, Small Batch