Place butter in a light-colored saucepan over medium heat; melt and swirl until milk solids turn golden brown and fragrant.
Remove butter from heat immediately and transfer to a heat-proof bowl to cool to room temperature.
Preheat your oven to 350°F and prepare a cupcake pan with liners.
In a large bowl, whisk together the flour, sugar, and baking powder.
In a separate bowl, whisk together the cooled brown butter, eggs, and vanilla paste until well combined.
Gradually incorporate the wet mixture into the dry ingredients.
Whisk in the whole milk until the batter is smooth and well-incorporated.
Divide the batter evenly into prepared cupcake liners.
Bake for 18 minutes or until a toothpick inserted into the center comes out clean.