In a medium bowl, whisk together dry ingredients.
In a measuring cup, whisk together milk, vanilla bean paste, and vanilla extract.
Make a well in the center of the dry ingredients then pour the milk mixture into the center, followed by the melted butter.
Whisk until no lumps remain and batter is smooth and well combined.
Pour into a 470ml microwave-safe mug.
Microwave on high for approx. 100 seconds.