Place all the butter, sugar, eggs, flour, baking soda, baking powder, and vanilla in a blender or processor; pulse until fairly smooth.
Add the milk, pulsing the blender as you add it, until it is mixed and the mixture is smooth.
Divide the mixture into a 12 cup cupcake tin that has been sprayed with cooking spray.
Bake at 400 degrees Fahrenheit for 15 to 20 minutes or until a nice golden color. Test for doneness by inserting a toothpick into a bun and pulling it out to see if it comes out clean.
After the buns have cooled for about 3 minutes in the pan, remove them carefully and let them cool on a wire rack.
You can freeze the leftovers for another time, in a ziplock baggie.