Prepare. Gather your ingredients. Also, you can give your ramekins a quick spray with nonstick if needed.
Chocolate. Place your butter and chocolate chips into a microwave-safe bowl. Microwave the ingredients, stopping to stir every 30 seconds until melted.
Whisk. Allow the mixture to sit for two minutes and then whisk in the eggs, yolks, and vanilla until fully incorporated.
Dry Ingredients. Add the flour and sugar to the bowl and whisk until just combined.
Ramekins. Evenly divide the batter between your ramekins, leaving about a quarter inch on top open.
Microwave. Cook each of the individual cakes until set in the center (about one and half to two minutes, depending on your microwave and the size of your ramekins).
Set. Let the cake sit for about a minute to cool to touch as microwaved food tends to take longer to cool in the center.