Preheat your oven to 350°F (175°C). Line a 12-cup muffin tin with cupcake liners.

In a large bowl, whisk together the flour, sugar, baking powder, and salt.

Add the softened butter to the dry ingredients and mix until the mixture resembles coarse crumbs.

In a separate bowl, whisk together the eggs, vanilla extract, and milk.

Gradually add the wet ingredients to the dry ingredients, mixing until just combined. Be careful not to overmix.

Divide the batter evenly among the prepared cupcake liners, filling each about two-thirds full.

Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean.

Let the cupcakes cool in the muffin tin for a few minutes before transferring them to a wire rack to cool completely.

In a large bowl, beat the softened butter until creamy.

Gradually add the powdered sugar, heavy cream, vanilla extract, and salt, beating until smooth and fluffy.

Divide the frosting into three bowls. Tint one bowl blue, one bowl red, and leave the third bowl white.

To decorate the cupcakes like the American flag, pipe or spread the blue frosting onto the top left quarter of each cupcake to create the 'stars' section.

Sprinkle white nonpareils or sprinkles over the blue frosting to represent stars.

Pipe or spread the red and white frosting in alternating stripes across the remaining part of the cupcake to create the 'stripes'.

Continue until all cupcakes are decorated.