01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
03 - In a large bowl, beat the softened butter, granulated sugar, and brown sugar with an electric mixer until light and fluffy, about 2-3 minutes.
04 - Beat in the egg, vanilla extract, and cotton candy flavoring until well combined.
05 - Gradually add the dry ingredients to the wet mixture, mixing on low speed until just combined. Do not overmix.
06 - Divide the dough evenly into two bowls. Add pink gel food coloring to one bowl and blue to the other, mixing gently until soft pastel shades are achieved.
07 - Pinch off a small piece from each colored dough and gently press them together to form a swirled ball. Place on the prepared baking sheets, spacing about 2 inches apart. Optionally, roll each ball in sprinkles before placing on the sheet.
08 - Bake for 9 to 11 minutes, until the edges are just set and the centers still look slightly underbaked.
09 - Let the cookies rest on the baking sheets for 5 minutes, then transfer to a wire cooling rack to cool completely.