Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a large bowl, cream together the butter, granulated sugar, and brown sugar until light and fluffy.

Beat in the egg and vanilla extract until well combined.

In a separate bowl, whisk together the flour, baking soda, and salt.

Gradually add the dry ingredients to the wet mixture, mixing until just combined.

Divide the dough into two bowls. Add the cotton candy flavoring syrup equally to both bowls, then add pink food coloring to one bowl and blue food coloring to the other. Mix until the colors are evenly distributed.

Take a small amount of pink dough and a small amount of blue dough, then gently roll them together to form a ball. Place the dough balls onto the prepared baking sheet.

Bake for 8-10 minutes, or until the edges are set and the centers are still slightly soft.

Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely. Garnish with pieces of cotton candy if desired.