Preheat the oven to 350°F (175°C) and line a muffin tin with cupcake liners.

In a large mixing bowl, cream together the softened butter and sugar until light and fluffy. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add the dry ingredients to the butter mixture, alternating with the milk, and mix until just combined.

Divide the batter evenly into three bowls. Leave one bowl plain, add red food coloring to the second bowl, and blue food coloring to the third bowl. Mix until the desired colors are achieved.

Spoon the colored batters into the prepared cupcake liners, layering them to create a striped effect (red, white, blue). Fill each liner about two-thirds full.

Bake in the preheated oven for 18-20 minutes or until a toothpick inserted into the center comes out clean. Allow the cupcakes to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.

Once cooled, frost the cupcakes with your choice of frosting and top with red, white, and blue sprinkles.