In a microwave safe mug (mine was about 12 ounces), whisk together all of the dry ingredients, but only 1 tbsp of chocolate chips.
Add in the wet ingredients and whisk until smooth (these mini whisks are perfect!). The batter should be pretty thick.
Top with the rest of the chocolate chips and wipe down the edges of the mug if desired.
Add to the microwave on high heat for 90-120 seconds. Mine was perfect at 100 seconds, but all microwaves are different. Because this cooks so quickly, even just 5 seconds can make a big difference (good or bad) so start with 90 and add more in small increments as needed. If you want a more gooey center, keep it on the low end, but if you want a well done standard cakey center, at least 100 seconds is ideal. It should just look done on top and not at all wet when it's done.
Remove from the microwave and let sit for about 5 minutes. Avoid diving in right away! It really needs to sit for a few minutes to settle.
Top with ice cream or whipped cream or enjoy as is!