Preheat your oven to 350°F (175°C). Line a 12-cup cupcake pan with paper liners to prevent sticking and make cleanup easier.

In a medium bowl, whisk together the all-purpose flour, baking powder, and salt. Set it aside for now.

In a large mixing bowl, beat the softened butter and granulated sugar together using a hand mixer or stand mixer. Beat on medium speed for about 2-3 minutes until the mixture is light and fluffy.

Add the eggs, one at a time, beating well after each addition. Then, stir in the vanilla extract. The batter should look smooth and creamy.

Gradually add the flour mixture to the butter mixture, alternating with the milk. Start and end with the flour mixture. Mix just until combined after each addition—be careful not to overmix!

Gently fold in the rainbow sprinkles using a spatula. This step is where the magic happens—those colorful sprinkles will be evenly distributed throughout the batter, making each bite a fun surprise.

Spoon the batter into the prepared cupcake liners, filling each about 2/3 full. This will give them room to rise without overflowing.

Place the pan in the preheated oven and bake for 18-22 minutes or until a toothpick inserted into the center of the cupcake comes out clean. Keep an eye on them toward the end to avoid overbaking.

Let the cupcakes cool in the pan for 5 minutes before transferring them to a wire rack to cool completely. Once cool, frost with your favorite frosting—whether it's a classic buttercream or a creamy cream cheese frosting—and top with a few extra sprinkles for that finishing touch.