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

In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla.

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

Fill the cupcake liners about 2/3 full.

Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Let cool in the muffin tin for 10 minutes before transferring to a wire rack to cool completely.

In a large bowl, beat the softened butter until smooth and creamy. Gradually add the powdered sugar, beating until light and fluffy. Add the milk and vanilla extract and beat until well combined.

Divide the frosting into bowls and add food coloring to each bowl to achieve the desired colors.

Frost the cooled cupcakes and decorate as desired with sprinkles, edible glitter, or other Taylor Swift-themed decorations.