Preheat oven to 350°F (175°C). Line a 12-cup muffin tin with cupcake liners.
In a large bowl, whisk together flour, sugar, baking powder, and salt.
Add the softened butter to the dry ingredients and mix on low speed until coarse crumbs form.
Beat in the eggs one at a time, then stir in the vanilla extract.
Gradually add the milk, mixing until just combined. Do not overmix.
Divide the batter evenly among the cupcake liners, filling each about two-thirds full.
Bake for 18-22 minutes, or until a toothpick inserted into the center comes out clean.
Let the cupcakes cool in the tin for 10 minutes before transferring them to a wire rack to cool completely.
Making the Buttercream Frosting
In a large bowl, beat the softened butter until creamy.
Gradually add the powdered sugar, alternating with the milk, beating until smooth and fluffy.
Stir in the vanilla extract.
Assembling
Once the cupcakes are completely cool, frost them generously with the buttercream frosting.
Notes
Store unfrosted cupcakes in an airtight container at room temperature for up to 2 days. Frosted cupcakes can be stored at room temperature for up to 1 day or in the refrigerator for up to 3 days.