Start by preheating your oven to 350℉ (or follow the instructions on the cake mix box), then brighten up your cupcake tin with some fun liners.
In a large bowl, mix the vanilla cake mix, eggs, salted butter, and whole milk until everything is fully incorporated. Mix everything together until smooth and thick. Be sure to scrape the sides of the bowl to capture all the goodness.
Spoon the batter into the liners, aiming to fill them roughly ¾ full for the perfect rise. Bake for around 18 minutes (use a toothpick, if it comes out clean, they’re ready). Give them a short rest in the tin, then carefully shift them to a wire rack to cool down fully.
For the frosting, beat unsalted butter until it’s light and fluffy, then add powdered sugar and heavy cream. Mix until it’s smooth and creamy. Too thick? Mix in a little more cream as needed to reach your perfect smoothness.
Divide the frosting into three bowls. Color one batch red, another blue, and leave the third untouched for a bright white. Now you're ready to start piping!
Start by piping blue frosting around the outer edge, add a ring of white in the middle, and top it off with a red swirl in the center.
For the final touch, top your cupcakes with festive sprinkles, edible stars, or whatever makes them pop with color and joy!