In an electric mixer fitted with the whisk attachment, beat together the butter, sugar, and eggs until ridiculously light and fluffy.
Add the flour, baking powder, and baking soda. Beat just until incorporated. Add the milk then continue to beat until a soft batter comes together.
Spoon into muffin tins lined with cupcakes wrappers, filling each just barely over 1/2 way full.
Bake in an oven preheated to 350 degrees for 17-19 minutes, or JUST until the cupcake springs back to the touch.
Remove from the oven and cool completely before frosting with Toasted Marshmallow Buttercream.