Start by melting the butter in the microwave for about 15 seconds.
In a bowl, whisk together the melted butter, brown sugar, granulated sugar, vanilla extract, and egg yolk until well combined.
Next, add the all-purpose flour and continue whisking until the mixture is smooth.
Measure out some chocolate chips and fold them into the batter, adding a few extra on top for good measure.
Microwave the mixture for 1 minute, making sure to pause halfway through.
