Serve these fluffy, frosted cupcakes at a birthday celebration or as a special dessert.
Adjust oven rack to middle position and heat oven to 350 degrees. Line 12-cup muffin tin with 12 paper liners.
In bowl of stand mixer (or large bowl if using handheld mixer), whisk together flour, sugar, baking powder, and salt. Lock bowl into place and attach paddle to stand mixer, if using.
Start mixer on low speed. Add softened butter, 1 piece at a time, and beat until mixture looks like coarse sand, about 1 minute.
Add milk and vanilla, increase speed to medium, and beat until light and fluffy, about 2 minutes. Stop mixer. Remove bowl from stand mixer, if using. Use rubber spatula to scrape down sides of bowl and stir in any remaining dry flour.
Use ⅓-cup dry measuring cup to divide batter evenly among muffin tin cups (use rubber spatula to scrape batter from measuring cup, if needed).
Place muffin tin in oven. Bake cupcakes until toothpick inserted in center of 1 cupcake comes out clean, 22 to 24 minutes.
Use oven mitts to remove muffin tin from oven (ask an adult for help). Place muffin tin on cooling rack and let cupcakes cool in muffin tin for 15 minutes.
Remove cupcakes from muffin tin and transfer directly to cooling rack. Let cupcakes cool completely, about 1 hour. (This is a good time to make the frosting! Click here for the recipe.)
Or just eat it with a spoon. (We won’t tell!) But if you do want to store your extra frosting, it can be refrigerated for up to 3 days. When ready to use, let frosting soften at room temperature for 1 to 2 hours, then rewhip on medium speed until smooth, 2 to 5 minutes. Frosting can sit at room temperature for up to 2 hours before using.