1. Cream the Butter and Sugars

• In a large bowl, cream together the softened butter, granulated sugar, and powdered sugar until light and fluffy.
• This should take about 2–3 minutes with a hand mixer or stand mixer.

2. Add Egg and Flavorings

• Add the egg, vanilla extract, and cotton candy flavoring (if using).
• Beat until fully incorporated and smooth.

3. Mix Dry Ingredients

• In a separate bowl, whisk together flour, baking soda, baking powder, and salt.
• Gradually add the dry ingredients to the wet mixture, mixing until a soft dough forms.

4. Divide and Color the Dough

• Divide the dough evenly into two separate bowls.
• Add a few drops of pink food coloring to one bowl and blue food coloring to the other.
• Mix gently until the desired shades are reached.

5. Swirl the Dough

• Pinch small pieces of pink and blue dough and press them together randomly to form a ball.
• Roll gently in your hands to create a marbled effect without overmixing.
• Optional: roll dough balls in sprinkles or edible glitter for extra flair.

6. Chill the Dough (Optional)

• Chill dough balls for 30 minutes if you prefer a thicker, puffier cookie with less spread.

7. Bake

• Preheat oven to 350°F (175°C) and line baking sheets with parchment paper.
• Place dough balls about 2 inches apart on the sheet.
• Bake for 10–12 minutes until edges are just set but centers are still soft.
• Do not overbake — they should remain slightly underdone in the center.

8. Cool and Serve

• Let cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.
• Enjoy warm or store in an airtight container.