Preheat the oven to 350 degrees. Take your cookie dough out of the package. Cut off about 1/4 of it, and then wrap up the larger section and place in the fridge.
Take the smaller portion you cut off and add in dark blue gel food coloring. Knead the coloring in really well and make it a little darker than you think you need it to be. Wrap this up and chill it while you work on your cookie cups.
For the cookie cups, grab about a tablespoon of the plain (uncolored) dough and roll it into a ball. Press one into each section of a mini muffin pan. You don't really need to press it down yet, just set them in there for now.
Take a teaspoon measuring spoon and dip the back of it in flour, then press down into each ball of dough to press it into each mini muffin cup. You'll need to twist it a bit, that'll help to form each cookie cup. Make sure to dip the back of your measuring teaspoon into the flour each time, so the dough doesn't stick.
Bake the cookie cups at 350 degrees for about 10 minutes. Let them cool completely. Once cool, twist the cookie cups to loosen them from the pan.
Now prepare your cookie stars. Take your blue cookie dough out of the fridge and roll it out using flour. You'll want to roll it out a little thin.
Cut out the stars using a small star cutter. Chill the dough until they're firm and then transfer to a cookie sheet.
Bake at 350 degrees for about 7 minutes. Let cool completely.
Prepare you buttercream using your favorite recipe. (You can find some on the blog here.) Once prepared, leave half of it white and color the other half red.
Place some white in a piping bag and some red in a piping bag. Cut off the end corners and pipe a couple lines onto some saran wrap. Roll them up into logs. You'll have a white buttercream log and a red buttercream log. Cut off the ends of the saran wrap and then place both buttercream logs into a new piping bag fitted with a Wilton 6B piping tip, or other large piping tip. (You're doing all this in order for the red and white buttercream to stay separated and not mix to make pink while piping it.) You'll probably have to do this a couple times to fill up all of the cookie cups.
Pipe in a small amount into each cookie cup and then pop on a blue cookie star.