Step 1

In a 16-ounce microwavable mug or small bowl, stir together flour, baking powder, cocoa powder, sugar, and salt.

Step 2

Using a fork, whisk in milk, oil, and vanilla extract until batter is smooth and there are no lumps. If mixing in a small bowl, pour into a 12 ounce mug (or larger) to cook. Otherwise, you can cook cake right in the bowl.

Step 3

Microwave cake for 30-45 seconds, then remove from microwave and add chocolate squares/chips into center of batter. There is no need to stir, as chocolate will sink to the middle.

Step 4

Place back in microwave and cook for an additional 30-60 seconds, or until cake rises and starts to pull away from the edges of mug and the center is almost firm, but still looks slightly shiny. Be sure to keep an eye on the cake as it cooks, as it might overflow if your mug isn't large enough.

Step 5

Let cool in microwave for 2 minutes, then remove and top with whipped cream or ice cream, if desired.