Prepare your cupcake pan, using your favorite cupcake liners.
Preheat oven at 325 degrees F.
Prepare another recipe of the white cake, tinting it at the end with blue gel food coloring, or any other color you wan to use, just make sure the stars and the other batter have different colors.
With a 2-2.5 inch star shaped cookie cutter, cut out stars out of the chilled cake sheet.
Place a star, standing on two of it's five little feet, in the center of each cupcake liner, and make you sure you put all of them on the same line, so that you will remember where the stars are facing. This is important. I like to put them paralel to the pan's edge.
Using a spoon, carefully spoon blue/colored batter in front, and back of the star, so that it is helps it stand. If you just pour the batter on top you risk the star to fall, and it won't stand strait. Keep adding batter in the cupcake liner, up to 2/3 of it's height, as you would normally do for regular cupcakes. Carefully place the pan in the preheated oven, and bake for 20 minutes. Check them with a toothpick to make sure they are done.
Let them cool on a wire rack in the pan.
Take a small sharp knife and make small superficial cuts on top of the cupcakes, all the way across, till the paper, on the same line as the stars inside, so after you take the cupcakes out of the pan, you will be able to see exactly what way the stars are oriented. The cut won't be obvious unless you look carefully.
Prepare your favorite cupcake frosting recipe. I used Swiss meringue buttercream on some , and cream cheese frosting on others. (left overs from the cake :) )
Frost the cupcakes to your liking, but remember not to cover the cut near the paper liner, so you can still see the sign you made, and so you can cut them when serving, to make the stars show up!
You can use this technique for making many fun cupcakes. You could make pink hearts inside of Valentine's Day cupcakes for example!