Combine chocolate chips and butter in a microwave-safe dish and melt in 30-second to 1-minute increments, stirring well between each interval.

In a separate bowl, combine the eggs and sugar and mix until lightened, about 2 to 3 minutes. Add flour and vanilla flavoring and mix until incorporated.

When chocolate mixture has cooled, combine it with the flour-egg mixture.

Pour batter into 4 large mugs or 6 small mugs.

Microwave on high from 50 seconds to 3 minutes depending on the power of your appliance and how many mugs you place in the microwave at once.

If you cook less, you may obtain a molten, lava center.

Top with whipped cream or vanilla ice cream in desired.