Preparation Steps

• Preheat oven to 350°F (175°C). Line baking sheets with parchment paper.
• In a large bowl, combine the cake mix, eggs, vegetable oil, and vanilla extract. Mix until well combined and a dough forms.
• Roll the dough into 1-inch balls and place them on the prepared baking sheets, about 2 inches apart.
• Bake for 10-12 minutes, or until the edges are lightly golden. Let cool on the baking sheets for a few minutes before transferring to a wire rack to cool completely.
• While the cookies are cooling, prepare the royal icing according to package directions. Divide the icing into three bowls.
• To achieve the desired consistency for flooding, whisk in 0.5 cup of powdered sugar with 3 tablespoons of water into each bowl, adding more water a teaspoon at a time if needed, until the icing falls in a thick ribbon.
• Tint one bowl of icing red and another blue. Leave the third bowl white.
• Once the cookies are completely cool, use piping bags or Ziploc bags with the corners snipped off to decorate. Outline each cookie with white icing, then flood the center.
• Immediately after flooding, drizzle thin lines of red and blue icing across the white icing. Use a toothpick to swirl the colors and create a marbled effect.
• While the icing is still wet, sprinkle with star sprinkles.
• Let the icing set completely before storing the cookies in an airtight container.