Preheat the oven to 325 degrees Fahrenheit. Place 24 regular-sized cupcake liners in muffin pans.

Place the sour cream, buttermilk, vanilla, eggs, and vegetable oil into a large mixing bowl. Whisk until smooth. Then sift in the cake mix and stir until smooth--but not overmixed. Do not skip sifting the cake mix because the batter will be lumpy.

Use a cookie scoop to divide the cake batter evenly between 24 cupcake liners.

Bake for 20-23 minutes or until the cupcakes are lightly browned and a toothpick inserted into the middle of a cupcake comes out clean or with a few small crumbs. Do not overbake. After 5 minutes of cooling time, move the cupcakes to a cooling rack. Cool completely before frosting.

Beat the butter, vanilla, butter flavoring, and salt with a mixer until creamy. Add the cream and stir. Add the powdered sugar, a cup at a time, and beat between each addition. If the frosting is too stiff, add more cream. If too soft, add more sugar.

Divide the frosting into 3 bowls. Set aside one bowl of white frosting. Add a small amount of red gel coloring to a bowl of frosting and stir to mix. Add additional color if needed until the desired shade is reached.

Add royal blue to another bowl of frosting. Stir to make a blue color. Add more blue if needed to reach the desired shade of blue.

Prepare 3 piping bags for the frosting by placing a coupler into each. Attach the frosting stars to the couplers and add the screws to secure the tips. Add a frosting color to each bag.

To create the flags, apply one color to all the cakes and then move to the next color.

Add white X shapes to all the cupcakes. First, place a star in the middle of a cupcake. Then add two more at 1 and 7 o'clock, as shown in the photos. Then place a star at 11 o'clock and another at 5 o'clock. Fill in with piped stars to connect them and make an X. Repeat these steps until all cupcakes have an X shape.

Fill in with blue stars in all the areas between the X shape. It does not have to be exact because these cupcakes are abstract flags. Repeat for all the cupcakes.

Add red crosses by overlaying stars on top of the blue areas. Place a red star in the middle of the white X. Then add one to the center edge of each blue section. Connect the stars by adding stars in between them. Then connect the other side up to the middle to make a line. Repeat to form a cross. Add this cross to all of the cupcakes.

Add red lines to each flag. First, remove the coupler ring and star tip from the red frosting bag. Add the number 2 round tip. Then make lines on top of the white X by tucking the piping tip into the red cross. Squeeze the piping bag and pull the piping tip up and away from the cupcake to make a string of frosting. Quickly lay the red frosting string onto the white, breaking it at the cupcake edge. Notice that the red lines are not in the middle of the white; instead, they should be placed close to the edge of the white. Starting clockwise, place the line closer to the upper blue section. Repeat for each section going clockwise. Then add red lines to all the cupcakes.

The final step is to outline the red cross in white using the number 3 tip. Pipe an "L" around each side of the red cross. Then repeat for each cupcake.