01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt until evenly distributed.
03 - In a large bowl, beat the softened unsalted butter, granulated sugar, and packed light brown sugar using an electric mixer until the mixture is pale, light, and fluffy.
04 - Beat in the large egg, vanilla extract, and cotton candy flavoring until the mixture is smooth and well combined.
05 - Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until just combined. Avoid overmixing.
06 - Divide the dough evenly into two separate bowls. Add pink gel food coloring to one bowl and blue gel food coloring to the other. Fold gently until soft pastel shades are achieved.
07 - Pinch off a small portion from each colored dough and gently press them together to form a swirled, multi-colored ball. Place each ball on the prepared baking sheet, spacing them about 2 inches apart. Optionally, roll each dough ball in colored sprinkles before placing on the sheet.
08 - Bake for 9 to 11 minutes, until the edges are just set and the centers appear slightly underbaked for a soft texture.
09 - Allow the cookies to rest on the baking sheet for 5 minutes, then transfer to a wire cooling rack to cool completely before serving or storing.